114 GEO. H. HORN, M. D. 



C. brevicollis Leo. [Helodes), New Species, 1865, p. 88. 

 C. exiguus Horn, n. sp. 



C. concinnus Lee. {Helodes), Proc. Acad, vi, p. 353. 

 C. obscurus Guer. {Elodes), loc. cit. p. 4. 



2}aUipes Lee. Proc. Aoad. vi, p. 354. 

 C collaris Guer. {Elodes), loc. cit. p. 4, fig. 22; Lee. loc. cit. p. 355. 



bico/or Lee. loc. cit. p. 355. 

 C. variabilis* Thunb. {Cantharis), Mus. Tips. 4, 54; Guer. loc. cit. p. 4. 



ovalis Say, Journ. Acad. 1825, p. 161. 



fusciceps Kby. Fauua Bor. Am. p. 245; Lee. loc. cit. p. 354. 



picea Lee. loc. cit. 



punctata Lee. loc. cit. 



nebulosa Lee. loc. cit. p. 355. 



modesia Lee. loc. cit. The last four are described as Helodes. 

 C. padi* Linn. {ChrT/somela), Syst. Nat. 2, p. 588; Guer. loc. cit. p. 7; Duval Gen. 

 Col. Eur. iii, pi. 37, fig. 181. 



pusilla Lee. {Helodes), loc. cit. p. 355. 

 C, impressus Lee. Proc. Amer. Philos. Soc. 1878, p. 405. 



PLACONYCHA n. g. 

 P. Edwardsii Lee. {Blcranopselaphus), Traas. Am. Eat. Soc. 1874, p. 57. 



EXPLANATION OF PLATE L 



1. — Macropogon piceus Lee, 1 a, tarsus of same, 1 b, base of antenna of 

 M. testaceipennis Motsch., 1 c, same of M. vufipes Horn. 



2. — Stenocolus scutellaris Lee. 



3. — Axioms piceus Lee, 3 a, hind tarsus. 



4. — Anchycteis velutina % Horn, 4 a, antenna of 9 > 4 b, hind tarsus. 



5. — Arceopus monachus Lee, 5 a, tarsus, 5 b, head and thorax from front. 



6. — Antenna of Ptilodactyla serricoUis Say, 6 a, hind tarsus. 



7. — Under side of Eucinetus terminalis Lee, 7 a, hind leg. 



8. — Ectopria nervosa 9 Mels., 8 a, 8 b, front of 9 and '^ , 8 c, 8 d, two forms of 

 male antenna, 8 e, antenna of 9 > 8 f^ tarsus, 8 g, claw of 'J, , 8 h, of 9 • 



9. — Claws of Eubria palustris Germ., a, the anterior, b, posterior. 

 10. — Acneus quadrimaculatus Horn, 10 a, antenna 9 ?j 10 b, tarsus, 10 c, claw. 

 11. — ^Thorax beneath of Prionocyphon, a, Ihnbatus, b, discoideus. 

 12. — Antenna of % P. discoideus Say. 

 13. — Claws of Odontonyx trivittis Germ. 

 14. — Posterior tarsi of Helodes. 

 15. — Scirtcs Troberti Guer. 

 16. — Placonycha Edwardsii % Lee, 16 a, antenna of 9j 16 b, tibia and tarsus, 



16 c, claws and appendages. 

 17. — Mentum, ligula and palpi of Helodes, (after Duval). 



*In these two species the European synonymy is omitted as not pertinent to 

 the present essay. 



