GUPPY : MOLLUSCA OF TRINIDAD. 217 



14. Helix ierensis Guppy. 

 *Amer. Journ. Conch.,' 1870, p. 307, pi. xvii., f. 4. 

 Crosse, 'Journ. de Conch.,' 1890, p. 40, No. 11. 



A horny-brown trochiform very obliquely costulate deeply 

 umbilicate little shell of about five whorls. Height 2 mill., 

 diameter 3 mill. The character of the ornamentation in this 

 and the following species is rather that of slightly irregular 

 lamellae instead of minute regular rounded riblets as in the 

 preceding species. 



It has occurred to me that this and the following are two 

 forms (or perhaps sexes) of the same species ; and a similar 

 idea has also occurred to me in reference to Zonites iinplicaus 

 and umbratilis. I am not in a position to advance any evidence 

 in support of this view. 



The Helix gtiatimak/isis of Crosse and Fischer ('Journ. 

 de Conch.,' 1873, p. 274, pi. ix., f. 3), and the If. cacoides of Tate 

 ' Amer. Journ. Conch.,' 1868, p. 155, pi. xvi., f. 3), seem to be 

 closely akin to if not identical with this. 



15. Helix caeca Guppy. 

 Crosse, I.e., p. 40, No. 12. 



This resembles the preceding in most characters, but 

 differs in being more elevated and less openly umbilicated. 

 The form of the whorls gives also a more circular contour to 

 the aperture. 



16. Orthalicus undatus Brug. 

 Shuttleworth, Not. Mai. p. 63, pi. iii., f. 4—5. 

 Bulimus zebra Guppy, 'Ann. & Mag. Nat. Hist.,' Jan. 1866, 



p. 48. 

 Orthalicus zebra Crosse, 'Journ. de Conch.,' 1890, p. 41, No. 15. 



Bland (' Amer, Journ. Conch.,' 1868, p. 185) remarks on 

 this, " The apical whorl in the Trinidad shells (and also in 

 the Florida specimens) is of a dark purplish brown color. 

 Shuttleworth describes the apex of O. zebra as immaculate." 

 D'Orbigny's figures of the shell (under the name of B. zebra) 

 are very good ('Moll. Cuba,' pi. vi., f. 9 — 10.) 



