76 VERMETID^E. 



flattened concentric ring-like ribs, which are packed so closely 

 as to allow very little space between them ; they are some- 

 times arranged in joints or interrupted strangulations, denoting 

 probably the limits of successive curtailment ; under a micro- 

 scope the entire surface (especially the interstices of the ribs) 

 is seen to be marked lengthwise by excessively minute and 

 crowded striae : colour yellowish- or reddish-brown, occasionally 

 variegated by circles of a darker hue : spire none in the adult, 

 its place at the posterior extremity being closed by a solid 

 shelly plug, which slopes from the ventral margin to a bluntly 

 conical point on the opposite or dorsal side : month annular, 

 slightly contracted, and strengthened by the last-formed rib : 

 operculum brown or dark-horncolour, consisting of about a 

 dozen gradually increasing whorls, defined by a narrow raised 

 spiral line or suture ; they become less distinct towards the 

 centre, which- is concave. L. 0*125. B. 0-033. 



Habitat : Rather common in the coralline zone of 

 Dorset,, Devon, and Cornwall; Sandwich (Walker); 

 Guernsey (Barlee) ; Swansea, Tenby, and Barmouth 

 (J. G. J.) ; Bantry Bay (Thompson and J. G. J.) ; Ar- 

 ran Isle, co. Galway (Barlee) ; Clyde district (Norman 

 and Robertson) . I do not consider it a British fossil ; 

 for I believe the shells described and figured by Searles 

 Wood from the Coralline Crag are not this species, but 

 his C. mammillatum. Philippi, however, has given it as a 

 Sicilian fossil, under the name of Odontidium rugulosum ; 

 and Professor Homes includes it in his great work on 

 the Miocene formation near Vienna. It inhabits the 

 coast of Brittany, beyond low-water mark of spring- 

 tides, according to Cailliaud ; M f Andrew dredged it in 

 8 f. at Vigo ; and several authors have noticed it as 

 Mediterranean (both on the European and African 

 coasts) and Adriatic ; on sponges from the Archipelago 

 (Bean); Canary Isles, 50 f. (M f Andrew); Cuba (Philippi) . 



Clark informs us that the animal is not at all shy, 

 and that all the specimens which he examined had an 

 ovary. He expressed some doubt whether the branchial 



