NO. 1441. AMEIUCAX PALEOZOIC INSECT,'^— II ANDLIRSCH. 781 



LITHOMYLACRIS Scudder. 



Front wing- .><lendor, almost lancet shaped, 3 times as long- as l)r()ad. 

 Costal area triang-ular, extending two-thirds the length of the wing, 

 with veins issuing radially from one point. Radius continuing almost 

 horizontally through the middle of the wing, with (5 l)ranches, the sec- 

 ond and third of which are furcate. Media stretching oblicjuely to 

 the extremit}' of the inner margin, with 2 forked and one simj>ie 

 branches running out forward. Cubitus advancing oT)liquely to the 

 inner margin, with one simple and 2 furcate ])ranches. Anal area 

 proportionally small, more than twice as long as high, and occupying 

 only two-lifths of the posterior margin. 



LITHOMYLACRIS ANGUSTA Scudder. 

 LitJiomi/l.acrls angiista Sci'DDKk, Mem. Boston Sor., HI, 1S79, p. 4<S, jd. v, fig. 2. 



LoeaJ'dy. — Port Griffith Switchback, near Pittston, Pennsylvania. 

 Anthracite series; E coal. 



Ilolotijpe.—O<ii. No. 38094, U.S.N.M. 



SPHENOMYLACRIS, new genus. 



Front wing subcordate, with slightly curved anterior margin, and 

 more strongly arcuate inner border, not quite twice as long as l)road 

 at the base. Costal area fully three-fifths of the length of the wing in 

 extent, with several bunches of veins issuing from the )>ase. Radius 

 with 8 forked and one simple branches, the lirst 2 of which spring 

 from one })oint. The last branches end in the apical mai'gin. Media 

 divided into 2 furcate offshoots. Cubitus strongly vaulted and, with 

 its 3 forked and 2 simple veins, taking up the central portion of the 

 posterior margin. Anal area not quite twice as long as high, extend- 

 ing three-sevenths the length of the wing, and limited by a quite 

 straight fold, in which the lirst anal vein fuses; the 6 remaining anal 

 veins are somewhat curved, and with their extremities turned toward 

 the tip of the wing; the}" end, however, in the normal way in the 

 inner margin. The structure consists of line, indistinct, irregular 

 cross lines. The humeral angle is broadly rounded, not })roduced into 

 an angle. 



