A STUDY OF THE GENUS MONOXIA — ^BLAKB 161 



nent, and from guttulata by the elytra being convex and not impressed. 

 In his description of debilis, lie states that debilis most closely resembles 

 obtusa, but the claws are distinctly cleft with the inner portion acute 

 and shorter than the outer one. 



In the LeConte collection are the three specimens mentioned by 

 LeConte under obtusa, two bearmg the round green label indicating 

 the locality Kansas and the third with the label "Andover." All 

 three are females with simple claws, and all are pale yellow-brown 

 without elytral markings. The specimen with the label obtusa, 

 which also bears the Museum of Comparative Zoology type No. 4383, 

 and the one from Andover are alike, but the third specimen, although 

 closely resembling these, represents an entirely different species, with 

 shallower, denser elytral punctation and with a prothorax quite dif- 

 ferently shaped. LeConte's description of obtusa without doubt is 

 based on this as well as the other two specimens. He described the 

 prothorax as being widely impressed on the sides, and this applies to 

 this specimen rather than the other two. The first Kansas specimen 

 bearing the label obtusa and the one with the label Andover are females 

 of LeConte's species debilis. Since LeConte himself gives as the chief 

 distinction between debilis and obtusa the fact that obtusa has simple 

 claws, in reality a mere sex difference, it seems best to regard these two 

 specimens (females of debilis) as LeConte's obtusa, which Horn has 

 already synonymized with debilis, and to describe as a new species the 

 second of LeConte's Kansas specimens. This is treated later in this 

 paper as M. inornata. 



In his descriptions LeConte emphasizes the fact that obtusa and 

 debilis have convex elytra without depressions and also that the elytra 

 are covered with a dense, silvery, pale pubescence, and unlike any of 

 his descriptions of the other species of Monoxia he describes the elytra 

 as being deeply ("profunde") punctate, the punctures being stronger 

 anteriorly. These are the most striking characteristics of the species. 

 M. debilis may be distinguished (1) by its size, which approximates 

 that of guttulata and angularis; (2) by the shape of its prothorax, which 

 is unusually long, and with the width considerably less than twice the 

 length; not greatly depressed, the basal angles not at all prominent, and 

 with a small, acute tooth; (3) the moderately dense silvery pubes- 

 cence, not so long and not so fine as in some species; (4) the elytral 

 punctation, which is unusually deep, well spaced and not at all 

 confluent anteriorly; in guttulata and consputa the punctures are much 

 denser; (5) the convex elytra, without depressions. 



As Horn states, the locality Andover, Mass., is evidently a mistake. 

 Specimens have been examined from the following localities: Alberta 

 (Medicine Hat, Edmonton); Idaho; Montana (Whitehead); North 

 Dakota (Mott); Kansas; Colorado (Colorado Springs, near Durango, 

 La Plata County; Garland, Manitou, Pingree Park, Ridgway, Rocky 



