270 CAPULID.E. 



colour varying from pale yellowish-white to dull reddish- 

 brown, rarely milk-white : epidermis arranged in concentric 

 layers, which are often fringed by a row of leaf-like or tri- 

 angular points ; it is easily rubbed off, and seldom remains on 

 the upper part: beak in adult specimens overhanging the 

 posterior side, and gradually becoming spiral with from two 

 to three whorls, which are placed sideways, and separated by 

 a distinct and rather deep suture : mouth extremely open, in 

 consequence of the expansion of the base: inside lustrous, 

 either porcelain-white or having a rosy and sometimes lovely 

 pink tinge ; it is concentrically and microscopically lineated 

 from the middle to within a short distance of the margin (as 

 in the FissureUidce); and the border of the margin is marked 

 lengthwise with longitudinal lines, which run at a right angle 

 to the other set of lines ; margin in young specimens finely 

 notched or scalloped : muscular scar horseshoe-shaped, with the 

 opening in front and the broad ends on each side of the neck. 

 L. 1-5. B. 1-75. 



HABITAT : Attached to rocks and large shells, and 

 especially frequenting oyster- and scallop-beds, from 

 7 to 85 f. on all our coasts ; low- water mark to 20 f. in 

 the Clyde district (Norman); 110-145 f. off the Mull of 

 Galloway (Beechey). Norwich Crag at Bramerton 

 (Woodward, fide coll. Wigham); Red and Coralline 

 Crag (Wood) ; newer tertiaries of Belgium and France 

 (Nyst) ; upper miocene bed at Antibes (Mace) ; Parma 

 (Menard de la Groye); North Italy (Brocchi); Sicily 

 (Philippi). Its existing distribution comprises the 

 North Atlantic sea-bed lying between Oxfjord in North 

 Finmark (Sars), south coast of Iceland (Wallich), and 

 Gibraltar (M* Andrew) , also both sides of the Mediter- 

 ranean, the Adriatic, and ^Egean ; the depths given by 

 different observers range from 5 to 105 f. 



Dr. Turton mentions, in the ' Zoological Journal 9 

 (ii. 566), "a thin laminar under valve/' which he 

 noticed on removing a live specimen of C. Hungaricus 

 from an oyster ; and he therefore conjectured that the 



