GASTEROPODA. G7 



slightly acuminated at the base ; left lip reflected, with a small open umbilicus, and 

 three very minute folds upon the columella. 



Aaiis, ^ of an inch. 



Localifi/. Cor. Crag, Sutton. 



But a few specimens of this species have come into my possession. It appears to 

 be distinct from the preceding one in the angular form of volution, and in being more 

 elongated, with a shght inflection of the outer lip at the angle of the volution. In all 

 my numerous specimens of C. costeUifera there are none presenting the angular form of 

 volution so distinct in this shell ; it is nevertheless possible it may be only a variety 

 of that species. 



Two worn specimens from the Red Crag, in my cabinet, much resemble the 

 C. IcEviiiscuht of ' Min. Conch. ;' they are in a mutilated condition, and may probably 

 have been introduced from the London clay. 



Trichotropis, Broderip and G.B. Soicerhy. 1829. 

 Trichopheke. Besh. 1830. 

 Trichopodus. Swains. 1840. 



Gen. Char. Shell turbinated or subfusiform, with spiral ridges or carinae upon the 

 volutions, generally thin ; spire more or less elevated, with an acute apex ; aperture 

 subovate, acuminated at the base ; columella obliquely truncate and flattened, with an 

 open umbilicus. In a recent state it is covered with an epidermis, and has a corneous 

 operculum, with a lateral nucleus. 



A few species only of this genus are yet known, and those are boreal forms. The 

 name was given from the hairy keels (%i^, r^iy^oq, hair, and roo-Kiq, keel) which surround 

 the species, forming the type of the genus. The animal is said to resemble in many 

 of its characters that of the genus Buccinum, connecting it with Cancellaria ; the shell, 

 however, differs from the latter in having a form of aperture like that of Purpura, with 

 a flattened columella, and also in the absence of oblique folds. 



1. Trichotropis borealis. Brocl. and Soio. Tab. VII, fig. 17, a — h, and 



Tab. XIX, fig. \\,a—h. 

 Trichotropis borealis. Brod. and Sow. Zool. Journal, 1829, vol. iv, p. 375. 



— Gould. Inv. of Massach. p. 300. 1841. 



Trichotropis acuminata. Jeffreys. MS. 



— cosTELLATVs. Couihoxuj . Bost. Journ. Nat. Hist. vol. ii, p. 108, pi. 3, fig. 2. 



Fosus UMBiLicATCS. Smith. Mem. of Wern. Nat. Hist. Soc. vol. viii, p. 50, pi. 1, fig. 2, 1838. 



Tr. Testa ovato-fusiformi; spird elevafd, c/jxice acmninaio; anfractihus sex, convexis, 

 cinffulatis, superne planmscidis ; longitudinaliter tenuisshne striatis ; aperturd ovatd, sub- 

 canaliculatd ; lahio complanato ; umbilico prof undo. 



Shell ovato-fusiform, with six deeply-defined volutions, and an elevated spire ; 

 whorls rather flattened above, ornamented with four or five elevated transverse, 



