DESCRIPTION OF RECENT SPECIES. 107 



dredged by Mr Smith, off the coast of Bute. In colour it resembles 

 Pecten obsoletus, but is somewhat more triangular in form ; from that 

 species, however, it is easily distinguished by the lineations of its 

 surface, which is adorned by numerous regular minute rays rugosely 

 striated, and crossed by regular undulated transverse somewhat dis- 

 tant strise. The rays on the upper surface are furnished with short 

 broad obtuse spines, crowning the convex flexure of the undulated 

 strise ; the spines only exist towards the margin on the lower valve. 

 The rugose appearance of the longitudinal strise is caused by the in- 

 terstices being punctate. Fig. 2.* represents a portion of the surface 

 magnified. — F. 



3. PATELLA FORBESII. N. S. — Smith. 



P. testa tenuissima, pellucida, obovata, gibba, aurantia, striis 

 longitudinalibus regularibus tubcrculatis, vertice versus marginem in- 

 flexo. Lon. T % ; lat. |. 



The regular tuberculated longitudinal strise radiating from the sub- 

 marginal apex, at once distinguish this species from any of its allies 

 among the British Patella. In form, it resembles the Lottia pul- 

 chella. The margin behind the apex is truncated, and the colour of 

 the shell is orange-yellow. When the animal shall have been ex- 

 amined, it may prove to be a Lottia. 



Dredged by Mr Smith in Rothsay Bay, adhering to a case-bottle, in 

 ten fathoms water. Fig. 3.* is a magnified view. — F. 



FOSSIL SPECIES. 

 4. PANOP^A BIVON^E. — Phillippi. 

 See remarks at p. 23. 



5, 6, 7, 8, 9. Various states of Fusus Peruvianus. 

 See remarks on this shell in the description of Plate I. 



10 & 10* (Magnified), nucula gibbosa. n. s. — Smith. 



N. testa ovata, lsevi, gibbosa, subinsequilatera, margine integer- 

 rimo. Lon. T % ; lat. '§. 



Very different from any of the existing British species. Its near- 

 est ally among extinct Nuculse is the Nucula tenuis of Phillippi; it 

 is, however, not so insequilateral as that species, but should it even 

 prove identical with the Sicilian shell, it must still retain its name, 

 as the name given by Phillippi is pre-occupied. The shell appears 

 to have been covered by a brown epidermis, and the hinge has eight 

 teeth on each side of the very prominent beaks. 



From the Newer Pliocene deposit at the Greenock Railway.— F. 



