96 ROYAL SOCIETY OF CANADA 



equally abundant. It varies a good deal in colour, as does I. interstinctus 

 also, but is usually much darker than that species. 



An exceptional!}' pale specimen was named Leptochiton punctatus, by 

 Mr. Whiteaves, under the supposition that it was a new species. 



ISCHNOEADSIA, Shuttleworth. 



338. IscHNORADSiA Mertensii, Middendorff, sp. 



Chiton Mertensii, Midd., Ball. Acad. Sci. St. Peters., vol. vi., no. 8. p. 118 (April, 1847); 

 and Mai. Ross., pt. 1, p. 125, no. 16, pi, xiv., fig. 1-8 (1847). 



This species is found, but not ijlentifully, in most localities examined 

 from Victoria to the (^ueen Charlotte Islands. 



It is most frequently obtained by dredging, but is sometimes found 

 between tides. Some very large specimens were collected by myself on 

 the rocks at low water at Salt Spring Island. 



339. IscHNORADSiA TRiFiDA, Carpenter, S]?. 



Trackydermon trifidus, Cpr., Kept. Brit. Assoc, 1863, p. 649 (August, 1864) ; and 

 Proc. Acad. Nat. Sci. Phila., 1865, p. 60. 



The type s]5ecimen of this rare species was collected by Dr. Ken- 

 nerley in Puget Sound. Two specimens were obtained by Dr. Dawson, 

 one at the mouth of Cumshewa Harbour in twentj^-nine fathoms, and 

 the other in Queen Charlotte Sound. 



Quite lately Dr. JSTewcombe has found one or two specimens near 

 Victoria. These are all the British Columbian specimens I hiwe heard 

 of, and to the north of us I. trifida is equally rare. 



NUTTALLINA, Carpenter. 



340. NuTTALLiNA scABRA, Eeeve, sp. 



Chiton scabra, Reeve, Conch. Icon., Mon. Chitons, pi. xvii., fig. 106 (1847). 



Dr. Kennerley is said to have collected one young living specimen 

 in Puget Sound. Dall gives the distribution of the species as "Vancou- 

 ver District, south to California, probably in the southern jslands of 

 Alaska ; at and above high- water mark, in crevices of the rocks ; at 

 Monterey abvmdant." 



I have seen numerous Californian specimens but have never found or 

 seen a British Columbian example. 



MOPALIA, Gray. 



341. MoPALiA ciLiATA, Sowerby, sp. 



Chiton ciliatns, Sowerby, Conch. 111., p. 79, 1838 

 = C. muscosus, Gould, Proc. Bost. Soc. Nat. Hist., vol. ii., p. 145 (Jul}-, 1846); 



and U. S. Expl. Exped., Mollusca, p. 313, fig. 436(1852). 

 var. Hindsii, Gray, Proc. Zool. Soc. London, 1847, pp. 69 and 169. 



