AMERICAN PHILOSOPHICAL SOCIETY. 



439 



10. B. flavicaudus. 



11. B. proximus. 



12. B. l?evum. 



13. B. variegatum. 



14. B. tetracolum. 



Trechus. 



1. T. conjunctus. 



2. T. partiarius. 



3. T. rupestris. 



Dytiscus. 



1. D. fimbriolatus. 



2. D. verticalis. 



3. D. mediatus. 



4. D. tfeniolis. 



COLYMBETES. 



1. C. erythropterus. 



2. C. fenes trails. 



3. C. ambiguus. 



4. C. seriatus. 



5. C. nitidus. 



6. C. bicarinatus. 



7. C. venustus. 



8. C. glyphlcus. 



9. C. obtusatus. 

 10. C. stagninus. 



Laccophilus. 



1. L. maculosus. 



2. L. proximus. 



Hydropokus. 



1. H. undiilatus. 



2. H. opposltus. 



3. H. niger. 



4. H. catascopium. 



5. H. lacustris. 



6. H. affinis. 

 Hydkocanthus. 

 H, iricolor. 



Haliplus. 



1. H. 12-punctatus. 



2. H. triopsis. 



Gykinus. 



1. Gr. americanus. 



2. Gr. emargiiiatus. 



3. Gr. analis. 



4. G. llmbatus. [ 7 ] 



Order and Section.-^COLUOFTUEA PENTA3IERA. 

 Tribe I.—ENTOMOPHAGA. Family IL—CARABICI. 



BRACHINUS Web. Fabr. 

 Anterior tibia emarginate ; elytra truncated at tip ; palpi fili- 

 form; labium subquadrate ; neck none; abdomen with interior 

 vesicles inclosing a caustic, volatile, and detonating fluid ; nails 

 simple. 



B. FUMANS. — Ferruginous ; elytra blue-black; venter, testa- 

 ceous-black. 



Brachinus fumans, ferruginous ; elytra blackisli-azure. Fabr. Syst. 

 Eleut., p. 219. 



Body ferruginous, with numerous minute hairs ; head, front 

 longitudinally impressed, each side near the base of the an- 

 tennae ; thorax with a longitudinal impressed line from the head 

 to the scutel ; scutel minute, blackish-brown ; elytra blackish- 

 azure ; about seven slightly impressed, very obtuse grooves, more 

 distinct near the suture, and obsolete at the outer margin ; sepa- 

 rating lines rounded ; venter dark reddish-brown. 



Length eleven-twentieths of an inch. 



Kather common under stones, &c., in various parts of North 

 America. In common with the other species of the genus, it 

 discharges from the posterior extremity of the body, when [8] 

 alarmed or irritated, a caustic fluid; this is remarkable by an 

 1828.] 



