449 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
rated, interspaces broad, flat or nearly so. Legs wanting. Length, 
as preserved, 5.60 mm., in life somewhat greater. 
Described from one specimen. 
Type.— No. 2,473 M. C. Z. Florissant, Col. (No. 11,731 S$. 
Scudder Coll.). 
At first sight, this mieot resembles an Acmaeodera, but cannot 
enter that genus on account of the distimct mesoscutellum and sepa- 
rateelytra. Behind the mesoscutellum is a narrow wedge-like sclerite, 
probably equivalent to the ‘‘second scutellum”’ of Chlamys, but there 
is no way of determining whether it was visible during life of the fossil, 
when the elytra were closed. A similar structure is seen in the Floris- 
sant fossil which I described some time ago under the name Acmaeo- 
dera schaeffert, but my figure of that species does not show the line 
of division between the two parts. Ptosima gibbicollis, our common 
North American representative of the genus, exhibits the same 
arrangement in about the same proportions, but it is necessary to 
open the elytra to see it. Since the size, form and sculpture of P. 
silvatica are similar to those of P. gibbicollis, | have assumed them to 
be congeneric if the lines are not too closely drawn. It will be better 
to consider that both of the Florissant insects which I have deseribed 
under Acmaeodera (A. schaeffert and A. abyssa) belong rather to Pto- 
sima, though they differ in sculpture of the elytra. 
AGRILUS PRAEPOLITUS, sp. Nov. 
Plate’ 3; tig. 7, 
Form only moderately elongate, less so as a fossil than in life on 
account of crushing by pressure. Head large, transversely suborbien-| 
lar, longitudinally finely striate anteriorly, occipital region mie | 
closely punctulate. Antennae moderately serrate but very poorly 
preserved. Pronotum, as preserved, flattened so as to increase the 
apparent width which is equal to twice the length, apex broader than’ 
the base which is distinctly bisinuate, sides rather weakly arcuate, 
front angles prominent, the left hind one with a strong arcuate carina. 
Surface not very coarsely but deeply punctured, the punctuation clos. 
and transversely confluent so as to form a reticulate pattern of inter: 
vening raised lines. Scutellum broader than long, not triangular 
but with a narrow posterior lobe, distinctly transversely carinate. 
Elytra not or scarcely sinuate along the outer margin, apices merel} 
ee 
