OK THE CEEITHIOPSIDES PBOM THE NORTH ATLANTIC. 89 



On the CeritJiiopsides from the Eastern Side of the North 

 Atlantic, with three new Species from Madeira. By the 

 Eev. E. BooG Watson, B.A.,r.E.S.E., E.L.S., Hon. Fellow 

 of the Naturwissenschaftlich Verein Llineburg. 

 [Eead 15th January, 1885.] 

 (Plate IV.) 

 The whole of the Madeiran Cerithiopsides, except G. Metaxce, 

 Chiaje, so much resemble the large elongated variety of C. tuber- 

 ctolaris, Mont., that for their determination the points of differ- 

 ence alone require to be noted ; but for the sake of comparison, 

 and to remove confusion between the little-known species of 

 the group, I add here some notes of all the species found in 

 the North-east Atlantic, none of which, so far as I know, have 

 been adequately figured. On the Mediterranean species I do 

 not enter, in the hope of speedily seeing them fully described and 

 figured by the Marquis de Monterosato, to whose kindness I am 

 indebted for the knowledge of them, and who has already given 

 some valuable notes on the group in the ' Journal de Conchylio- 

 logie,' 1874, p. 274, 1877, p. 41, as well as in his ' Enumerazione 

 delle Conchiglie mediterranee,' p. 39, and more recently in his 

 ' Nomenclatura di alcune Conchiglie mediterranee,' p. 124. 



I have not included in this list the G. pulchella, C. B. Adams, 

 from Jamaica, nor the Massachusetts species, viz. G. Emersonii, 

 C. B. Ad., G. terebrans, C. B. Ad. (which, teste Dr. (xwyn Jeffreys, 

 is a Gerithiu'm=-G. trilineatum, Phil., of the Mediterranean), and 

 G. Whiteavesii, Yerrill (which Dr. Grwyn Jeffreys asserts to be 

 GeritJiimn metula, Loven, not the Mediterranean species thus 

 called by Delle Chiaje). These lie beyond the limits I have as- 

 signed my self ; and the same is the case as regards the two species 

 from Wydah in the Bight of Benin (see Proc. Zool. Soc. Lond. 

 1871, p. 736, pi. Ixxv. figs. 21 & 22), regarding which, however, 

 I may say that G. carinata, E. A. Sm., is certainly distinct from 

 any North-Atlantic species, and that G. gemmulifera has suffered 

 from exfoliation so as to have become unrecognizable. 



The species with which I have to deal may be classified thus : — 

 I. Those with a smooth apex. 



1. Apex somewhat stiliform. 



(1) Gerithiopsis tubercularis, Mont. 



(2) G.Jefr-ei/si, Wats. 



2. Apex not stiliform. 



(3) G. costulata, Moller. 



LINN. JOTJEN. — ZOOLO&Y, VOL. XIX. 7 



