1852.] 169 



appendage. The following scheme may aid the student in determining the 

 species, which in the western part of the continent will become quite numerous 

 and very difficult. 



A. Ungues omnes appendiculati. 



a. Thorace transverse, marginibus integris, Sp. 1 8. 



b. Thorace elongato, raarginibus integris, Sp. 9. 



c. Thorace lateiibus serrulatis, Sp. 10 17. 



B. Ungues non appendiculati, Sp. 18 19. 



A a. 



1. D. fuse us, fusco-subaeoeus, dense fusco-pubescens, obesus, thorace 

 longitudine duplo latiore, lateribus valde rotundatis, elytra convexis, subtilius 

 sat dense punctulatis, pedibus rufo-piceis. Long. -14. 



Valleciias, California, May. The male has the thorax wider than the elytra, 

 which are a little narrowed posteriorly. 



2. D. suturalis, oblongus nigro-feneus, subtiliter cinereo-pubescens, 

 dense nigro-pilosellus, thorace iatitudine paulo breviore, lateribus paulo rotun- 

 datis, angulis posticis obtusis, elyiris confertim punctulatis et subrugosis, 

 sutura lateribusque densius cinereo pube?centibus. Long. '13 '15. 



San Diego, California. In the male the elytra are narrower than the thorax, 

 and narrowed posteriorly. 



3. D. c n f r m i s , nigro-aeneus, subtiliter cinereo-pubescens, dense nigro- 

 pilosellus, oblongus, thorace Iatitudine breviore, lateribus et angulis posticis 

 valde rotundatis, elytris confertim punctulatis et subrugosis, sutura saepius 

 densius cinereo-pubescente. Long. 12- 14, 



San Diego. Very similar to tbe Nst, and only differing in the form of the 

 thorax; the male has the elytra slightly narrowed posteriorly. 



4. D. sordidus, oblongus, convexus, aeneo-piceus, longius sordide 

 pubescens, et nigro-pilosellus, thorace Iatitudine breviore, parce subtiliter 

 puntulato, lateribus rotundatis, elytris sat dense minus subtiliter punctatis. 

 Long. "14. 



San Diego abundant; distinguished by the equally distributed coarse pubes- 

 cence and longer more numerous erect black hairs. The male is e, little nar- 

 rower than the female. 



5. D. griseus, oblongus, convexus, aeneo-piceus, densius longe sordide 

 pubescens, non pilosellus, thorace Iatitudine breviore, punctulato, lateribus 

 rotundatis, elytris sat dense grossius punctatis, pedibus antennisque rufis. 

 Long. -1. 



One specimen, California, (San Diego?). The joints of the antennae are not 

 transverse, and from the 4th 10th are equal in size. The preceding species 

 have the antennas serrate only from the 5ih joint. 



6. D. brevicornis, oblongo-cylindricus, aeneo-piceus, dense subtiliter 

 longe cinereo-pubescens, non pilosellus, thorace Iatitudine breviore, punctulato, 

 lateribus valde rotundatis, elytris sat dense grossius punctatis, pedibus anten- 

 nisque rufis, his articulis a 4to subtransversis. Long. -1. 



San Diego. A little narrower than D. griseus, and with more rounded thorax. 

 The antennae are shorter, the joints from the 4th are transverse, and the Vth and 

 8th are a little narrower than those which precede them. 



7. D. squalidus, oblongo-elongatus, aeneo-piceus, subtiliter longe'cinereo- 

 pubescens, nigro-pilosellus, thorace transverso parce punctulato, lateribus paulo 

 rotundatus, angulis posticis obtusis, elytris sat dense grossius pucctatis, dorso 

 leviter depressis. Long. 09. 



San Diego, two specimens. Resembles most nearly D. suturalis, but is 

 smaller ; the posterior angles of the thorax are less distinct, and the elytra less 

 finely punctured. As in D. suturalis, the 4th joint of the antennae is scarcely 

 dilated. 



