496 MR. H. N. RIDLEY ON THE 



shells found attached to rocks, wlieu placed upon a flat surface, 

 rest upon the anterior and posterior margins only, so that the 

 sides are slightly raised. 



39. Chiton (Iscitnochitok ?) pectinatus, Sotverly. 



Chiton pectiuatus, Sotverby, Con. III. pi. 174. f. 146; Reeve, Con. Icon. 

 pi. 26.f. 133. 



Hab. ? (Beeve): "West Indies (P. P. Carpenter in Brit. 



Mus.). 



The marginal scales are not at all well drawn by Sowerby, 

 being much too elongate. 



40. Chiton (Ischnochiton) caribbjeorum, Carpenter. 

 (Plate XXX. figs. 5, 5«.) 



Testa elougato-ovalis, vix carinata, varie picta, griseo-olivacea, 

 albo, rufo et olivaceo pieta, vel purpurea, interdum nigrescens, 

 albo virgata, valvis terminalibus concentrice et rugose granoso- 

 striatis vel squamatis, ceutralibus liris tenuissimis granosis cur- 

 vatis flexuosis ornatis, areis lateralibus rugose granosis vel squa- 

 matis ; valva postica pone apicem centralem leviter concava ; 

 ciugulum minute squamatum, squamis minutis elongatis ovalibus 

 indutum, pallide i-oseo-griseum, dilute nigro tessellatum. 



Lougit. 27 millim., diam. 9. 



Hah. St. Thomas {Brit. Mus.). 



The above appears to be a manuscript name attached to speci- 

 mens in Cuming's collection which are identical with few shells 

 from Fernando Noronha. The colour is very variable, some 

 specimens, when viewed fi'om a distance ot'twelve inches, appearing 

 olive-grey speckled with white ; others are of a pinkish cream- 

 colour speckled with red or blotched along the sides in front of the 

 lateral areas with black, as in some of the specimens from Fernando 

 Noronha. The granules or scales of the lateral area and on the 

 front and posterior valves are peculiai'ly flat and are somewhat 

 transversely arranged on the former and concentrically on the 

 latter. The central areas are finely punctured along the centre, 

 and become more and more coarsely grauosely lirate as the sides 

 are approached. One example is almost entirely reddish purple, 

 and others are blackish with a broad pallid stripe down the middle 

 from end to end. 



41. Chiton (Acantiiochiton) astrioer, Beeve. 

 Chiton astriger. Reeve, Conch. Icon. pi. xviii. f. 109. 

 Hah, Barbados. 



