PINNA. 



Plate XXVIII. 



Species 52. (Mus. Cuming.) 



Pinna bamulosa. Finn, testa triyond, marline postico 

 recto, antico flexuoao-rotmidato, tenui, semipellucido- 

 corned, radiatim liratd, liris conspicui sqtiamaik, 

 squamis tubulom, acute erectis, irregularibus, latere 

 antico mutico. 



The branched Pinna. Shell triangular, straight at 

 the posterior edge, flexuously rounded at the ante- 

 rior, thin, semitransparent-horay, radiately ridged, 

 ridges conspicuously scaled, scales tubular, sharply 

 erect, in'egular, anterior side smooth. 



Bab. West Indies. 



h light, transparent-horny shell, profusely beset with 



erect, spouted scales, variously directed. 



Fig. 53. (Mus. Cuming.) 

 The shell here figured, Pinna ingens of Pennant, Brit. 

 Zool. vol. iv. p. 115, and Lamarck, Anim. sans vert. vol. vii. 

 p. 66, proves to be a smooth state of the British P. pec- 

 tinata, and presents a remarkable instance of variation 

 in growth. It is of a dull, nebulous, horny colour, with- 

 out a vestige of the scales which characterize the type of 

 the species ; it has, however, the radiating posterior ridges. 

 It appears to be uniformly of large size, and is more 

 rounded. 



August, 1858. 



