6 TROCHID^. 



Dr. p. Fischer. 



Monog. Genre Troque, in Kiener's Coquilles Vivantes, Paris, 

 1880. 

 R- A. Philippi. 



Monograph of Trochus in Syst. Conchylien Cabinet, ed. 2 

 (1846 to about 1856). 

 LovELL Reeve. 



In Conchologia Iconica vol. xiii. (1861.) 

 Adams' monograph contributes numerous descriptions of supposed 

 new forms, without figures, measurements or comparison with known 

 species. The work as a whole is an unmitigated nuisance. Philippi's 

 monograph describes scores of " species " founded upon coloration or 

 other equally trivial characters. His descriptions are generally 

 very good, and the figures assist one to identify most of the forms. 

 Reeves' work is very incomplete. The monograph by Fischer is an 

 altogether thorough and reliable work. 



The primary division of the Trochid?e is attended with consider- 

 able difficulty. I have adopted the following four 



Subfamilies. 



Trochininj<:. Animal with frontal lobes; jaws wanting; lateral 

 teeth never more than 5 on each side of the rhachidian, or some- 

 times with an obsolete sixth tooth. Shell pearly ; peristome incom- 

 plete. 



GiBBULiNiE. Frontal lobes present ; jaws present ; lateral teeth 

 frequently exceeding 5 on each side. Shell pearly ; peristome in- 

 complete. 



IjMBONiiNiE. Rostrum short, rounded, with lateral beards; eyes 

 on long peduncles ; tentacles subulate, the left attached to a siphon- 

 shaped frontal appendage; mantle reflexed over the edge of the 

 aperture ; jaws present ; lateral teeth 6 on each side. Shell polish- 

 ed, scarcely pearly, peristome incomplete. 



Delfhinulin.e. No frontal lobes ; jaws present. Shell pearly in- 

 side ; aperture circular, peristome continuous. 



Synopsis of Genera and minor groups. 



Subfamily I. Trochinin^. 



Genus TROCHUS Linne. 



Shell conical, strong, imperforate or false-umbilicated, the axis 

 always solid, the spire more or less elevated, whorls numerous, 



