474 bulletin: museum of comparative zoology. 



Type — No. 2,629 M. C. Z. Florissant, Col. (No. 507 S. H. 

 Scudder Coll.). 



Intermediate in size between D. exesa and D. boivditchiana, both 

 from these shales. 



DiABROTICA FLORISSANTELLA, Sp. nov. 



Plate 11, fig. 3. 



Form similar to that of the living D. longicornis. Head of moder- 

 ate size, the antennae showing only nine joints but these, if straight- 

 ened out, would reach fully two thirds of the distance to the abdominal 

 apex. Prothorax short, the form too much distorted for description. 

 Elytra distinctly but finely longitudinally striate, the striae apparently 

 not punctured. Legs normally slender. Length, 6 mm. 



Described from one specimen. 



Tiipc— No. 2,630 M. C. Z. Florissant, Col. (No. 9,566 S. H. 

 Scudder Coll.). 



While the species of Florissant fossils assigned to Diabrotica do not 

 offer any very striking characters, it seems worth while to give this 

 one a name since if fairly well preserved it will usually be separable 

 from the other three by the long antennae and the distinct elytral 

 striae. 



Diabrotica exesa Wickham. 

 One specimen, No. 2,631 M. C. Z. (No. 9,193 S. H. Scudder Coll.), 



Trirhabda sepulta, sp. nov. 

 Plate 11, fig. 6. 



Form about like that of the recent T. canadensis. Head finely 

 punctate, the punctures extensively confluent forming rugae. Anten- 

 nae (possibly not preserved to the extreme tip) not quite as long as 

 the elytra, the basal five joints proportioned about as in T. convcrgens. 

 Prothorax with the disk scarcely visibly punctulate, sides only feebly 

 arcuate. Elytra not at all striate, sculpture very minute. The entire 

 upper surface of the body, including the antennal joints, is clothed 

 with fine hairs, quite close-set on the elytra but less so on the head and 

 pronotum. Legs wanting. Length, 7.70 mm.; of elytron, 5 mm. 



Described from one specimen. 



