NO. 1930. DESCRIPTTONS OF NEW SAWFLIEl^—ROHWER. 213 



are those adopted by the writer. They are in the main those used by 

 Hartig where the points here mentioned are figured. There is, as far 

 as known, but little antigeny in this genus. 



The Japanese species of this genus form a distinct group, but are 

 congeneric with the t^^pe of the genus. . 



Key to the North American species. 



Males 1 



Females 5 



1. Labrum sharply angular apically; cochlearium short, and broader apically 2. 



Lab rum obtusely angular or rounded, apically; cochlearium long, and not decidedly 



broader apically 3_ 



2. Abdomen beyond the propodeum reddish; metanotum coarsely punctured; third 



antennal joint much longer when compared with the fourth; stigma oblique 



apically tarckim. 



Abdomen entirely black; metanotum nearly impunctate; third antennal joint but 

 little longer than the fourth; stigma truncate apically angulahre. 



3. Antennal ridges obsolete; area between the ocelli and orbit coarsely sculptured 



planifrons. 



Antennal ridges distinctly present; area between the ocelli and orbit very sparsely 



sculptured 4_ 



4. Apical joint of hind tarsi subequal in length with the two preceding, the third and 



fourth joints more robust; cochlearium as in figure 2c atroviolaceum. 



Apical joint of hind tarsi distinctly shorter than the two preceding joints, the third 



and fourth joints slender and more elongate; cochlearium as in figure 2e 



peratrum. 



5. Abdomen beyond the propodeum reddish 6. 



Abdomen entirely black 7_ 



G. Antennal ridges well defined; area between the ocelli and eyes coarsely sculptured; 

 apical angulation of labrum with the sides gently sloping so the angle is broader. . 



erythrogastrum. 



Antennal ridges obsolete; area between the ocelli and eyes sparsely sculptured; 



apical angulation of labrum with a more acute angle tardum. 



7. Antennal ridges well defined at least just below ocelli peratrum. 



Antennal ridges obsolete 8. 



8. Sheath distinctly oblique below; lower apical margin of napes scarcely produced; 



wings blackish planifrons. 



Sheath rounded nearly evenly; lower apical margin of nates decidedly produced; 

 wings brownish atroveolaceum. 



LAGIUM TARDUM (Norton). 



Allantus tardus Norton, Boston Journ. Nat. Hist., vol. 7, pt. 2, 1860, p. 246, No. 21. 

 Tenthredo atroviolacea var. tardus Norton, Trans. Amer. Ent. Soc, vol. 2, 1869, p. 

 240; Norton Catalogue, p. 172. 



What is determined as this species agrees with specimens deter- 

 mined by Crssson from Massachusetts and also specimens in American 

 Entomological Society's collection. It seems probable that Norton's 

 type is lost, although it may be in the Peabody Museum. Judging 

 from the material in the collection this is a northern species, there 

 being no specimens from farther south than Washington, District of 

 Columl)ia. 



