THE CANADIAN ENTOMOLOGIST. 253 



Leng and Hamilton* place obtusus Casey and orcgoiicnsis Lee. as syn- 

 onyms of scutcllaius; but all three of them appear to be distinct. Col. Casey 

 has transferred orcgoncusis** Lee. to the dentiform group, but the writer feels 

 he must have mistaken a black form of maculosus for that species: this would 

 account for the description of monticola Casey, which appears to be the 

 true orcgonensis Lee. 



The most strongly maculated species are titillator, maculosus, obtusus 

 and inannorator. M. maculosus may be densely black or reddish brown, al- 

 though the red-brown individuals are probably newly emerged. ' 



The length of the antennae varies greatly within the limits of each 

 species and appears to the writer to be of little specific importance. The sexes, 

 however, can be separated by antennal characters, since the females of all 

 species have the antennae but little longer than the body, often with the seg- 

 ments bicolored, while the males have the antennae much longer than the 

 body and the segments as a rule unicolorotis. 



The size varies greatly in each species apparently according to the con- 

 dition of the food supply. Individuals are generally smaller in arid sections 

 where the recently fallen or cut timber dries rapidly. 



The key to the species herein submitted is based upon an examination of 

 the material in the Oregon Agricultural College, very kindly loaned by Profes- 

 sor Lovett. the material in the collection of the California Academy of Sciences, 

 that in the private collection of Dr. F. E. Blaisdell and Dr. E. C. Van Dyke, the 

 Ottawa collection of the Entomological Branch and that of the author. 



M. angusticollis is known only from the description. Of the species in- 

 cluded in the table the writer has examined the following number of adults : — 

 12 marmorator, 17 obtusus, 85 maculosus, 50 titillator, 102 orcgonensis, more 

 than 200 notatus and over 500 sciitellatus. 



Key to Species. 



A. Apices of elytra produced into an acute spine or blunt process. 

 B. Process of elytral apex arising from sutural angle. 



C. Process of elytral apex slender, acute or subacute ; body and antennae 



comparatively slender ; punctation of elytra sparse and fine, ashy ves- 



titure in more or less definite areas; general color reddish titillator Fab. 



CC. Process of elytral apex blunt; body comparatively short and robust; 



punctation of elytra dense and coarse, ashy vestiture more or less 



diffused; general color black or rufous maculosus Hald. 



BB. Process of elytral apex not arising from sutural angle. 



C. Process of elytral apex arising from the rounded apices, spinous 



angusticollis Casey 



CC. Process of elytral apex arising from the obliquely prolonged apices ; 

 vestiture of elytra often in definite patches ; general color yellowish 

 brown marmorator Kirby 



♦Transactious Am. Ent. Soc, 1890, XXIII, p. 109. 

 **Me'moirs on the Coleoptera, IV, 1913. 



