AMERICAN COLEOPTERA. 63 



they do not appear to me distinct in any important respect; the outer 

 striae of the elytra are somewhat more obliterated in the latter than in 

 the former. 



THROSCUS Latr. 

 T. validus, nigro-piceus, fusco-putx'Hceiis.capite convexo punetato, hand cari- 

 nato, oculis eonvexis ; tliorace fortiter punetato, puiietis subvariolosis ; elytris 

 tenuiter striatis, striis parce punctatis, interstitiis subbiseriatiin puuctatis, 

 tarsis pieeo-testaceis. Long. 5 iiiin. 



One specimen, California. This species is allied to T. puncfafus 

 Bonv., but differs by the strite of the elytra being very fine, and but 

 slightly impressed; they are marked with distant punctures larger 

 than those of the intervals, which are arranged .somewhat in two irre- 

 gular series. 



T. sericeus, fuscus ."ubrufescens, pube helva appressa brevi dense vestitus, 

 oapite punctulato, bicarinato, carinis integris, oculis profundc impressis; tho- 

 race confertim punetato ; elytris striis bene impressis, punctatis, interstitii.s 

 .subbiseriatini punctatis : antennis obscure ferrugiiieis. tarsis flavo-testaceis. 

 liong. 2-a mm. 



Three specimens from San Francisco given me b}' Mr. Like. This 

 species resembles i.n form T. Clicvrolatii Bonv., but the head is more 

 strongly bicarinate, and the pubescence is much shorter, finer and 

 denser; by this last mentioned character, it differs froui all the other 

 species known to me. 



PACTOPUS Leo. (n. g, Throseidte.) 



This new genus is founded upon an undescribed Californian insect, 

 resembling in its characters and form Throsciij;. except that the anten- 

 nx instead of being clavate are fusiform, and the hind tarsi are re- 

 ceived in deep narrow grooves impressed on the first, second and third 

 ventral segments in the same manner as the grooves for the middle 

 tarsi in both genera are inipi-essed on the metasternuni. 



It will therefore be only necessary to give at present a description 

 of the antenna? to enable this genus to be recognized. 



Antennae a little longer than the head and thorax, received in very 

 deep sinuous grooves, which terminate in the space under the hind 

 angles of the prothorax ; 1st joint obconical, nearly twice as long as 

 the 2d, which is slightly transverse; 3d — 7th nearly square, closely 

 articulated, about equal in thickness to the 2d, 8 — 10th very little 

 larger, also quadrate and closely united, 11th one-half longer, pointed 

 at the tip. 



Tarsi long and slender, received in grooves, which are well (kifiiied ; 

 those for the middle pair are on the metasternuni, divergent, and 



