40 THE CANADIAN ENTOMOLOGIST. 



Elytra suboval, distinctly rounded on the sides dilaiaius- 



Elytra parallel, sides straight or but little rounded. 

 Prothorax not narrowed behind. 



Prothorax semielliptical, widest at extreme base; elytra 2^j lo 4 

 limes as long as the prothorax, brownish testaceous frequently with 



a pinkish tinge aiigustatus. 



Prolhorax with sides parallel posteriorly; elytra 2^3 to 3 times as 



long as the prothorax, fuscous in colour rinconis. 



Prothorax obliquely narrowed behind, widest at about the middle. 

 Antenna? 8-jointed, i)rothorax more coarsely and densely reticulate 

 punctate, less shining, the median line carinate or subcarinate 



posteriorly odarthrus. 



Autenna? lo-jointed, prothorax more sparsely punctate and shining^ 

 median line sulcate posteriorly decarthrus. 



So far as known, dilatatus is confined to the Cape region of Lower 

 California. Angusiaius occurs in and to the west of the Sierras from 

 Southern California to Oregon. 



There is a confusing disagreement in published references to Micro- 

 photus as to the number or antennal joints. LeConte, in the original 

 diagnosis of the genus (based on dilatatus), describes these organs as 

 ii-jointed. In his subsecpient description of angiistatus they are said to 

 be 9 jointed. Later, in his synopsis of the l/impyridiv, the number of 

 joints is given in the generic table as nine in the male and eight in the 

 female, but in the remarks upon the genus which follow on the same page 

 the males are said to have jo and the females 9 jointed antenna?. The 

 small subulate appendage to the terminal joint was evidently counted by 

 LeConte in the original desciption, but not afterwards. So far as my material 

 gots decart/irus îiXouth^iS 10 jointed antenna?; of my three examples of 

 dilaiatu% one has three organs 9 jointed, another 8-jointed, the outer joints 

 being lacking in the third. \\\ both specimens of rinconis the antennae 

 are evidently 8-jointed when viewed from the front, but there is a more or 

 less complete division of the sixth joint on the lower and posterior sides 

 so that viewed from that position they appear to be 9 jointed. In the 

 t\g\\i t\^.m\i\ts o{ Oct art hr us the antennre are uniformly 8 jointed, while 

 in angustatiis they are as constantly 9 jointed. The following measure- 

 ments in millimeters of the length and width of the i)rothorax and the 

 length of the elytra exhibit considerable variation, but the deduced ratios 



