164 [September, 



-'^ 2. C. m argini c ollis , niger cinereo-pubescens, supra nigro-pilosellue, 

 capite vix punctulato, thorace laevi transverse, rufo-marginato, elvtris cyaneis, 

 confertissime subtiliter punctatis, abdomine sanguineo. Long. -2. 



San Diego, California ; one female, with the antennae piceous, except the 

 three basal joints, which are rufous. The thorax is more transverse and less 

 rounded on the sides than the next sp'3cies, and the discoidal black spot is so 

 large as to leave only a narrow red margin. 



3. C. nigriceps Er. Entom. 56; Malaehius nigriceps Say, Journ. Ac. 

 3, 183; Am. Ent. 3, pi. 48. 



Middle and ISouthern States. 



4. 0. e X i m i u s Er. Entom. 56. 



New York. Very similar to the preceding, bat the anterior femora are yel- 

 low, and the abdomen sanguineous, without black spots. 



5. C. tricolor Er. Entom. 57 ; Malaehius tricolor Say, Journ. Ac. 3, 182 ; 

 Am. Ent. 3, pi. 48. 



New York and Lake Superior ; a variety with the lateral margin of the elytra 

 more distinctly rufous, is found in Missouri Territory. 



6. C. punctatus, niger subtiliter cinereo-pubescens, supra dense nigro- 

 pilosellus, capite confertim subtiliter punctato, thorace laevi rufo, transverse, 

 lateribus et basi valde rotandatis, eljtris alutaceis, confertim punctatis. 

 Long. '17. 



Two females from Missouri Territory; the antennse are black, with the 

 two basal joints rufous ; the body beneath is black, with the coxae inclining to 

 rufous. 



7. C. cribrosus, aeneo-niger, cinereo-pubescens, supra nigro-pilosellus, 

 thorace laevi, rufo, transverso, lateribus valde rotundato, macula magna discoi- 

 dali nigro notato, elytris convexis viridibus grosse punctatis, pedibus anticis 

 testaceis. Long. -15 -17. 



San Diego, California, under sea weed. The male has the antennae entirely 

 rufous ; in the female the external joints are piceous, with their outer angles 

 rufous. 



8. C. q u a drim ac ul at us Er. Entom. 58. Malaehius ^-macidatus Fabr. 

 Syst. El. 1, 308. 



Common in the Middle and Southern State?. 



9. C. confluens; niger, cinereo-pubescens, supra nigro-pilosellus, capite 

 Subtilissime punctulato, thorace rufo transverso, ad latera punctulato, elytris 

 confertissime punctatis rufis macula basali alteraque majore postica fere con- 

 fluente viridibus, abdomine sanguino. Long. -17. 



Missouri Territory, two females ; the antennae are piceous, with tbe four 

 basal joints pale ; the spots on the elytra are so large as to leave only the suture 

 and margin red ; the red is wider at the middle, both on the suture and margin, 

 "while in the next species, the external margin alone is dilated. From both C. 

 4-maculatus and C. vittatus it is easily distinguished by the finely punctured 

 Bides of the thorax. 



10. C. vittatus Er. Entotu. 60; Malaehius vittotus Say, Journ. Ac. 3) 

 184 ; Am. Ent. 3, pi. 48. ( 5 ) Megadcuterus llaworthi Westwood, Tr. Ent- 



Middle States, rare. 



11. C. marginellus, niger, densins cinereo-pubescens, supra nigro- 

 pllosellus, capite thoraceque subtiliter pnnctulatis, hoc tenuiter rufo marginato, 

 transverso, elytris cyaneis confertim punctatis margine ad medium latiore sutu- 

 raque rufis, abdomine pedibusque rufis. Long. -17. 



River Colorado, California ; the red margin of the elytra is dilated as in C. 

 vittatus. The antenna? of the male are entirely rufous, those of the feranle are 

 piceous, with three or four b-isal joints rufous. 



