17 
Key to the Species 
A Pronotum with anterior and basal constrictions feebly impressed, coarsely and 
rather sparsely punctured; elytra very coarsely and very deeply punctured; colour 
reddish testaceous; antennae very stout. ( ThesaMa Csy.). 
(1) gnathoides Lee. 
AA Pronotum with anterior and basal constrictions strongly impressed, punctation 
small and dense to nearly obsolete; antennse slender. 
B General colour of body reddish, with lateral and sutural black vittee on elytra; 
last ventral segment of male feebly excavated at apex and not spinose. 
(2) aurata Horn. 
BB General colour of body black; elytra black, or testaceous and black; last ventral 
of male very deeply excavated and bispinose. 
C Pronotum and head polished, minutely and sparsely punctate. 
D Elytra! punctation moderate, becoming minute on the apices. 
(3) ruficollis Say. 
DD Elytral punctation very coarse on the cephalic half, becoming rather small 
on the apices. (4) straussi Webb. 
CG Pronotum and head closely to very densely punctate. 
D Elytra testaceous, marked with arcuate sutural and straight, lateral, black 
vittse approximate or fused at the apical fourth, variably complete. 
(5) scripta Lee. 
DD Elytra black, each with a pale yellowish, median, longitudinal vitta. 
(6) densicoUis Csy. 
(1) Pidonia gnathoides Lee., 1874, Smith. Misc. Coll., vol. XI, No. 264, 
p. 228. 
Acmaeops lisa Leng., 1890, Ent. Am., vol. 1, p. 108. 
ruhriceps Csy., (Thesalia) 1913, Mem. on the Coleop., vol. IV, 
p. 198. 
Length 8 mm. Mr. Charles Schaeffer 1 remarks: “I possess through 
the kindness of my friend, Mr. Charles W. Leng, a specimen of his Acmaeops 
lisa fron Dunsmuir, California, which differs only from the type in having 
on each elytron a small black spot. It agrees exactly with a specimen of 
Leptura gnathoides from Tulare county, California, except that the thorax 
and underside are black.” 
A male and female before us each has a black spot midway on the 
sides. Of four specimens in the United States National Museum collection, 
Washington, from Washington state and California, two have the black 
spots and two are without them. The elytral vestiture of the female is 
noticeably finer and shorter, giving it a more shining appearance. 
The type of ruhriceps Casey differs from our compared specimen of 
gnathoides in being longer and narrower, with longer antennse, and with 
the pronotum somewhat more strongly tuberculate on the sides. It may 
eventually prove to be distinct. 
Six specimens examined, from Mariposa and Eldorado counties, Cali- 
fornia, and Washington state. In literature Oregon is also given. 
Type locality : Oregon, type a male. 
(2) Pidonia aurata Horn, 1869, Proc. Acad. Phila., p. 570. 
Length 8 to 10 mm. The colour is pale reddish with a sutural and 
sublateral black vitta on each elytron, variable in width, the sublateral 
vitta in some cases widened behind. 
Thirty-two specimens were examined from North Carolina, Penn- 
sylvania, and Virginia- 
Type locality: Alleghany Kidge, western Virginia. 
1 Bull. Brook. Inst., 1, 1908, p. 342. 
