CALYPTRACEA. MOLLUSCA. CREPIDULA. 157 



State Coll., No. 114. Soc. Cab., No. 1652. 



Patella Noachina, Lin.; Mantissa, 551. CHEMK. ; Conch., xi. 186, pi. 197, 



f, 1927, 1928. 

 Patella apertura, MONTAGU ; Test. Brit., 491, pi. 13, f. 10. WOOD ; Index, pi. 



38, f. 89. 

 Patella fissurella, MULLER; Zool. Dan., i. t. 24, f. 4 to G. GMELIN ; Syst. t 



3728, No. 193. 

 Fissurella Noachina, LYELL ; Obs. sur le Soullvcment de la Suede, No. 1C, pi. 2, 



f. 13, 14. LAM. ; An. sans Vert., vii. 604. SOWERBY; Conch. Illustr., (Fissu- 



re'lla) f. 15. 



Puncture'lla Noachina, LOWE ; Zool. Journ., iii. 77. 

 Cemoria Fleming!!, LEACH ; SOWERBY ; Conch. Man., f. 244. 

 Sipho striata, BROWN ; Conch, of Great Brit., fyc., pi. 36, f. 14 to 16. 



Shell bluish-white, conical, its summit pointed and turned 

 backwards, and the surface covered with about twenty-two ribs, 

 with intervening smaller ones, and wrinkled by the lines of growth. 

 A narrow, diamond-shaped slit is presented at the summit, which 

 opens in the interior by a circular aperture, towards the margin, 

 the course of this canal being as it were arched over by a thin 

 plate of the shell, when viewed within ; edge oval and scolloped 

 by the ribs. Length -J inch, breadth { inch, height ^ inch. 



This curious little shell, the only recent species of its genus 

 known, is frequently taken from the stomachs of fishes. It is also 

 an inhabitant of the northern seas of Europe, and is found in a 

 fossil state also. 



It has been arranged under different genera, but undoubtedly has 

 claims to be the type of a distinct genus. Besides those mentioned 

 above, the genus RI'MULA of Defrance, would also probably embrace 

 it. But CEMORIA has the priority over all those which have been 

 constructed, though any one of the others would seem to have been 

 better chosen names. Lowe remarks, that the P. apertura of Mon- 

 tagu has been ascertained, almost beyond a doubt, to be nothing 

 more than the young of Fissurella Grceca. But his figure repre- 

 sents this shell. 



GENUS CREPIDULA, LAM. 



Shell oval, arched, somewhat boat-shaped, with an imperfect 

 spire pressed against the margin ; cavity partially divided within 

 by a horizontal partition. 



