FFB: THE MYSTERY COMPANION and THE ARMCHAIR COMPANION edited by A. L. Furman (Gold Label Books, 1943 and 1944) and their sequels.

A. L. or Abraham Loew (or Louis) Furman, is apparently a man largely lost to time...William Contento's Index to SF Anthologies and Collections notes that he was "Manager of a publishing firm (Amour Press); lawyer; editor of juvenile [and adult -TM] books and anthologies"; his years are give as 1902-1972.  Ray Betzner on Facebook yesterday brought A. L. Furman back to mind for the first time in years; I remembered him for his YA anthologies mostly published around the turn of the 1960s with titles  (originally) given as Teen-Age ____ Stories or Young Readers' _____ Stories...which were notable, when I was sampling them as a reader of ten or twelve years old, for the utter mediocrity, at best, of nearly all the stories included (I think I missed Teen-Age Party Time Stories at that time, but can only imagine what camp value it currently has, for that matter instantly had). A(lice). M. Lightner was one of the better and more frequent contributors to his juvenile sf anthologies; no one as notable was included in his youngster's horror anthologies; Robert Arthur did a much better job, as did most other YA editors. But Betzner cited the first of his Mystery Companion annual series in his query for details about Furman, and this four-volume annual series looks far more promising, as one of the earlier US bugcrusher mystery/suspense/horror anthologies drawing most if not all its contents from the slick and pulp magazines. As there are (as far as I can find online) no full indices for any of the Mystery or the slightly later duo of Armchair Companions (there isn't even a complete contents of the Second Armchair Companion that I've found in searches over the last dozen hours or so), I figured I'd draw together what I could find. The earlier volumes of the series were published by Gold Seal Books, which as far as I can tell became Lantern Press in 1946, his primary publisher for the many later young readers' books as well (and their softcover line Lantern Pocket Books would reprint a number of those in paperback in the latter '60s and '70s; ISFDB currently mistakes the LPB line for Pocket Books reprints, as did I at first before a note by Steven Rowe--though that by the 1970s, YA line Archway/Pocket Books was the publisher of the Furman juvenile anthologies might have driven some confusion), as well as of the fourth Mystery and second Armchair volumes.

Index information brought together from WorldCat, The FictionMags Index and JG Mallard.

438 pages ; 21 cm New York : Gold Label Books, ©1943.

Active Duty · Richard Sale · ss  The Blue Book Magazine [v77 #1, May 1943]
The Body in the Ostrich Cage [Jimmie Lavender] · Vincent Starrett · ss  Mystery [v9 #5, May 1934]
The Sword of God  Hal Hode  
The Greek, Poropulos · Edgar Wallace · ss The Weekly Tale-Teller [#81, November 19, 1910]
Bond of Reunion  Carl Carmer  Saturday Review
Believe It or Die · Philip Ketchum · nv The Blue Book Magazine [v76 #5, March 1943]
Yours Truly, Jack the Ripper · Robert Bloch · ss Weird Tales [v36 #12, July 1943]
The Street of the Little Candles  James Francis Cooke
The Blackout Murder · Allan Vaughan Elston · ss Short Stories [v182 #4, #892, February 25th, 1943]
“You’re Killing Me!” · "Dale Clark"  (Ronal Kayser) · nv Street & Smith’s Detective Story Magazine [v166 #2, June 1943]
If the Dead Could Talk · Cornell Woolrich · ss Black Mask [v25 #10, February 1943] 
America’s Most Famous Murder · George L. Porter · ar (Lincoln assassination) Star Magazine [v2 #3, July 1931]
The Judge Finds the Body "Geoffrey Homes" (Daniel Manwaring) Maclean's
The Phantom Slayer · Fritz Leiber, Jr. · ss Weird Tales [v36 #3, January 1942
Tears of the Virgin Thomas Grant Springer
Me and His Majesty and Trouble  Joseph C. Stacy (hu)
Death in a Gray Mist · Frank Owen · ss  Weird Tales [v37 #1, September 1943]
A Pair of Gloves Carl Carmer
The Man in the Cask · Vincent Starrett · nv Real Detective Tales and Mystery Stories [v11 #2, June/July 1927]

The Mystery Companion: abridged paperback (missing five items from the original selection)  Popular Library (Canada) 1943; 192 pp.

Active Duty · Richard Sale · ss  The Blue Book Magazine [v77 #1, May 1943]
The Body in the Ostrich Cage [Jimmie Lavender] · Vincent Starrett · ss  Mystery [v9 #5, May 1934]
The Sword of God  Hal Hode  
The Greek, Poropulos · Edgar Wallace · ss The Weekly Tale-Teller [#81, November 19, 1910]
Bond of Reunion  Carl Carmer  Saturday Review
Yours Truly, Jack the Ripper · Robert Bloch · ss Weird Tales [v36 #12, July 1943]
The Street of the Little Candles  James Francis Cooke
The Blackout Murder · Allan Vaughan Elston · ss Short Stories [v182 #4, #892, February 25th, 1943]
“You’re Killing Me!” · "Dale Clark"  (Ronal Kayser) · nv Street & Smith’s Detective Story Magazine [v166 #2, June 1943]
If the Dead Could Talk · Cornell Woolrich · ss Black Mask [v25 #10, February 1943] 
The Judge Finds the Body "Geoffrey Homes" (Daniel Manwaring) Maclean's
The Phantom Slayer · Fritz Leiber, Jr. · ss Weird Tales [v36 #3, January 1942
Tears of the Virgin Thomas Grant Springer
Me and His Majesty and Trouble  Joseph C. Stacy (hu)
Death in a Gray Mist · Frank Owen · ss  Weird Tales [v37 #1, September 1943]

Second Mystery Companion (Gold Label Books 1944)  410pp

The bedchamber mystery / C.S. Forester --
Delayed verdict / Allan Vaughan Elston --
The question mark / Margery Allingham --
Ghosts don't make no noise / Richard Sale --
Post-mortem / Cornell Woolrich --
The chopsticks of Confucius / Vincent Starrett --
The master of the murder castle / John Bartlow Martin --
The riddle of the whirling lights / Stuart Palmer --
Death by accident / Francis Cockrell --
The man who amazed fish / Frank Owen --
There are more to die / Philip Ketchum --
Radio patrol / Leslie T. White --
Scoundrels by night / Richard Kent --
The fluted arrow / William Byron Mowery --
Steve takes a hand / Hugh B. Cave --
Connoisseur of murder / Joseph C. Stacey --
Biographies. 

Third Mystery Companion (Gold Label Books 1945) 395pp

The calling card of Mr. Engle / Louis Paul --
The unloaded gun / Allan Vaughan Elston --
The experts / Mindret Lord --
The Kiskadee bird / Elisabeth Sanxay Holding --
Face in the dark / High Pentecost --
Wet Saturday / John Collier --
One chance in a million / Will Payne --
Death had a pencil / Richard Sale --
The phantom of the Subway / Cornell Woolrich --
The mark of Maat / Sax Rohmer --
The third ladder / Philip Ketchum --
Hangin' crazy Benny / Leslie White --
The old man in the window / Margery Allingham --
The long still streets of evening / Frank Owen --
Crystal evidence / Donald Barr Chidsey --
The simple art of murder / Raymond Chandler --
The riddle of the blueblood murders / Stuart Palmer --
Ways that are dark / Thomas Grant Springer --
The case on Turkey Point / Howard Bloomfield --
The witness / William Brandon --
Murder at the opera / Vincent Starrett --
Biographies. 

Fourth Mystery Companion  (Lantern Press 1946) 396 pp

White carnations / Q. Patrick --
The painted nail / George Harmon Coxe --
Traitors trail / Hugh Pentecost --
The unbelievable baroness / Elizabeth Sanxay Holding --
A triumph in theory / Louis Paul --
The tenth clue / Dashiell Hammett --
The saint sits in / Leslie Charteris --
The white cat / Richard Kent --
The level crossing / Freeman Wills Crofts --
The case of the Calico dog / Mignon Eberhart --
Prelude to murder / Walter C. Brown --
Fog over Hong Kong / Vincent Starrett --
The adventure of the bearded lady / Ellery Queen --
Twice-trod path / William Irish --
Tomorrow we die / Frank Owen --
The important point / William MacHarg --
The secret of the ruins / Sax Rohmer --
Halloween assassin / Frederick Skerry --
Library book / Cornell Woolrich

The Armchair Companions:

The Armchair Companion (Gold Label Books, 1944)  367pp Set the wild echoes flying / by James Street -- A man's mother / by Gladys H. Carroll -- Afternoon of a faun / by Vincent Starrett -- The red sash / by Ketti Frings -- The good neighbors / by Conrad Richter -- The Empire City angel / by Eustace Cockrell -- Remember this day / by Arch Whitehouse -- Wild Bill Hiccup / by Cornell Woolrich -- The night gown / by Camilla Holland -- Sharp work at the Duck and Egg / by F.L. Smith -- Lady square / by Richard English -- The street of faces / by Frank Owen -- Flight of the wawkus bird / by Richard Sale -- Penthouse for Nellie / by Florence B. Alexander -- A big day for Mr. Vane / by Edward Stevenson -- Red wine / by T.G. Springer -- The deceiving husband / by Margaret A. Barnes -- The last charge / by Edison Marshall -- Camp follower / by Robert Carson -- A kiss for Mr. Lincoln / by Louise K. Mabie -- Biographies. Second Armchair Companion (Lantern Press 1946) 351pp Contributing authors include Beryl Markham, James Street, Richard Wright, Libbie Block, R.H. Newman Stories include: "The Splendid Outcast" by Beryl Markham, "One Day Late" by Dorothy Canfield,  "Saturday at Ten" by Vincent Starrett