[TAYLOR] MARINE MOLLUSCA 95 
333. TONICELLA MARMOREA, O. Fabricius, sp. 
Chiton marmoreus, O. Fab., Fauna Groenl., p. 420 (1780). 
This is a species that I have searched for, so far, in vain. So far as 
I know it has only been taken in the Pacific Ocean, near the Aleutian 
Islands (Dall), and at Japan, and by Dr. Dawson in Houston-Stewart 
Channel, Queen Charlotte Islands (two specimens). 
It is a common species on both sides of the Atlantic Ocean. 
CYANOPLAX, Pilsbry. 
334. CYANOPLAX HartweEail, Carpenter, sp. 
Chiton Hartwegii, Cpr., Proc. Zool. Soc. London, 1855, p. 231. 
{ 
335. CyanopLax NuTTALLII, Carpenter, sp. 
Chiton Nuttallii, Cpr., Proc. Zool. Soc. London, 1855, p. 231. 
CO. Nuttallii is recorded from Paget Sound (Swan), and © Hartwegii 
is said to have been found at the Queen Charlotte Islands by Dr. Daw- 
son. Dr. Pilsbry supposes the two to be forms of one species. My 
own specimens of ©. Hartwegii (1 have not met with the other form) 
are from Victoria, but they are not any of them quite like the typical 
Californian ones." 
ISCHNOCHITON, Gray. 
336. ISCHNOCHITON INTERSTINCTUS, Gould, sp. 
Chiton interstinctus, Gould, U. S. Expl. Exped., Mollusca, p. 322, pl. xxvii., 
figs, 423-423b (1852). 
This beautiful little species is very common. on stones and dead 
shells dredged in ten to thirty fathoms, at Victoria, Departure Bay and 
elsewhere. Dr. Dawson obtained it in Virago Sound and Houston- 
Stewart Channel, Queen Charlotte Islands, and in many more southerly 
localities. Occasionally small specimens may be found under stones 
between tides. 
337. ISCHNOCHITON RETEPOROSUS, Carpenter, sp. 
Trachydermon retiporosus, Cpr., Rept. Brit. Assoc., 1863, p. 649 (August, 1864) ; and 
Proc. Acad. Nat. Sci. Phila., 1865, p. 59. 
= Leptochiton punctatus, Whiteaves, Trans. Roy. Soc. Can., vol. iv., sect. iv., 
p. 125, figs. 3 and 4 (1886). 
This is usually found in company with the last species and is 

1 Since the above was written, Dr. Pilsbry has described this form, which occurs 
also in California, as a distinct species under the name 7rachydermon (Cyanoplax) 
Raymondi. Nautilus, vol. viii., p. 46 (August, 1894). 
