30 Journal New York Entomological Society. [Voi. xvii. 



A SHORT SYNOPSIS OF THE SPECIES OF OCHO- 

 Di^US INHABITING THE UNITED STATES. 



By H. C. Fall, 

 Pasadena, Cat,. 



Including the two new species described in the present paper, the 

 number of species of OchoJceiis known from within our faunal limits 

 is now nineteen. As the last review of the genus, that by Dr. Horn 

 in the Transartions of the Am. Ent. Soc, 1876, dealt with only eight 

 species a new synoptic table is believed to be opportune, and in order 

 that the student may be for many purposes relieved of the necessity of 

 consulting the scattered descriptions, reference is made to the 

 principal distinguishing characters of all previously described species. 



In the following table I have drawn less upon the form of the 

 mentum, and more on the cephalic armature and form of the sutural 

 angle of the elytra, as these latter characters may be more quickly 

 and accurately verified, the true form of the anterior portion of the 

 mentum being frequently difficult of determination. The order of 

 species will therefore be found to differ somewhat from that of Horn. 



Table of Species. 



1. Elytra punctate striate , 2. 



Elytra not punctate striate 9. 



2. Mentum elevated in the form of a transverse wedge. 



Prosternum strongly lobed in front, external outline of mandibles broadly arcuate, 

 sutural angle of elytra dentiform, basal joint of hind tarsi thickened, arcuate 

 and longer than the following joints united i. pectoralis Lee. 



Prosternum not lobed in front, external outline of mandibles ogival, sutural 

 angles of elytra not dentiform, basal joint of hind tarsi slender and shorter 



than the remainder 2. gnatho Fall. 



Men turn fl at or concave 3. 



3. Front or clypeus not at all tuberculate 4. 



Front with a distinct more or less acute or dentiform tubercle, except in pnesidii...'] . 



4. Sutural angle of elytra not dentiform 5. 



Sutural angle of elytra dentiform ; upper tooth of front tibia; nearer to the middle 



tooth than to the base 6. 



5. Vertex not carinate ; mentum deeply longitudinally impressed ; elytral strice feebly 



impressed and finely punctured. 

 Posterior tibiae of male with an acute tooth at middle, posterior femora of male 

 without apical tooth 3. simplex Lee. 



