38 [April, 



being more distinctly narrowed towards the base, and by the elytra being slightly 

 dilated from the base to the posterior third. 



I have great doubts of the propriety of separating this genus from Taphria ; 

 the very slight difference in the form of the last joint of the labial palpi, which 

 is less dilated in the American species, is surely insufficient. From the differ- 

 ence in the form of the ungues, noticed in the species below, I am inclined to 

 believe, that a natural arrangement would require all the genera (so called) of 

 this group, in which the mentum tooth is emarginate, the paraglossae longer than 

 the ligula, and the ungues serrate, to be united into one genus. The species 

 contained in Pristonychus, Pristodactyla and Taphria do not appear more dif- 

 ferent from each other than those embraced in Platynus. 



2. P. corvina, nigra, nitida, thorace ovali, postice vix angustiore, latitudine 

 non breviore, anulis posticis rotundatis, latenbus margine anguste reflexo, basi 

 utrinque late foveato, elytris thorace latioribus postice non dilatatis, striis pro- 

 fundis, bipunctatis, antennis palpis pedibusque runs, unguibus valde serratis. 

 Long. -46. 



Lee. Ann. Lye 4, 217. 



Pristonyckus americanus Lee. Proc. Acad. Nat. Sc. 2, 52. 



Pennsylvania and Georgia; not common. 



3. P. ad vena, nigra, subnitida, thorace subquadrato, postice subangustiore, 

 lateribus rotundatis, margine subreflexo, angulis posticis obtusis rotundatis, basi 

 utrinque late foveato, elytris thorace latioribus tenuiter striatis, bipunctatis, an- 

 tennis pedibusque nigro-piceis, unguibus basi subtilius serratis. Long. *3G 4. 



Lee. Ann. Lye. 4, 217. 



Lake Superior ; not rare on the northern shore; a specimen from the north- 

 eastern boundary of Maine was kindly given me by Mr. Brevoort. More slender 

 than any of the other species here described, and very similar in appearance to 

 some of the smaller European Pristonychus. The mentum tooth is much less 

 emarginate than in the preceding. 



4. P. dub i a, nigra, minus nitida, thorace obovato, postice magis angustato, 

 angulis posticis obtusis, rotundatis, basi depressa utrinque subfoveata^ elytris 

 thorace latioribus subellipticis, tenuiter striatis bipunctatis, antennis pedibusque 

 piceis, unguibus ba>i vix obsolete serrulatis. Long. -48. 



One specimen: New Mexico; collected by Mr. Fendler. The base of the 

 thorax is only about two-thirds as wide as the apex ; the dorsal line is fine, but 

 the transverse impressions are well marked. The mentum tooth is narrow, and 

 very slightly emarginate at the tip. 



In these four species, the under surface of the tarsi is glabrous, and the outer 

 margin of the two posterior pairs is deeply grooved. In my synopsis of Pteros- 

 tichus (Journ. Acad. Nat. Sc.,2d ser., vol. 2) it will be seen that in closely allied 

 species, the latter character is of little value. The same would seem to be the 

 case in the present group, and no better proof is required than the remarks made 

 by Baron Chaudoir, on the page immediately opposite that in which he insists 

 strongly on the great assistance which is derived from it in distinguishing Cala- 

 thus from Pristonychus. The real difference between the genera is precisely 

 that so long ago made known by Erichson, viz., the length of the paraglossae, 

 which in Calathus do not extend beyond the ligula, while in Pristonychus (and 

 likewise in Pristodactyla and Taphria) they are very distinctly elongated. 



Anchtjs Lee. 



Palpi tenues, acuminati, maxillares articulo ultimo paulo longiore ; antennae 

 filiformes, articulo lmo crassiore,. et longiore; mentum dente medio simplici; 

 ligula truncata, paraglossis angustis longioribus. 



A curious insect, having very much the appearance of Diaphorus, but having 

 the head less constricted posteriorly, and the elytra rounded at the apex ; the 

 thorax is long and cordate, almost turned into a pedicel at the base, with the 

 impressions elongate and very narrow ; the elytra are twice as wide as the thorax, 

 oblong and convex, with the humoral angles rounded, and the apex scarcely 



