BY J. c. COX. 429 



of Port Jackson and adjacent Coasts in P.Z.S. 1867, p. 185, No. 

 239, on p. 223, and also in Whitelege's List of Marine and Fresh- 

 Water Invertebrate Fauna of Port Jackson and Neighbourhood, 

 published in 1889 in Journ. and Proc. Royal Soc. N. S. Wales ; 

 it will have in future to be known as Onithochiton Lyellii, Sowerby, 

 having been described by him in 1832 in P.Z.S. p. 26, and 

 tigured by him in Conch, Illust., fig. 7. 



It was described by Reeve a second time in Conch. Icon, as 

 Ch. puncticulatiis, Sp. 69, pi. xii. fig, 69b. See Tryon and 

 Pilsbry's Manual of Conchology, Vol. xiv. p. 247, pi. LV. figs. 1-7. 



IscHNOCHiTON Haddoni, Pilsbry. 



One of our commonest Chitons^ it has hitherto been regarded 

 and catalogued as Ischnochiton longicymha of Q. et G. It will be 

 recognised as the Chiton in this harbour having a rather more or 

 less wide white dorsal stripe ; other specimens of it are of a light 

 buff all over ; others are brown, or speckled with olive-black, and 

 some show a decided red tinge. 



We are indebted to Mr. H. A. Pilsbry for showing that we 

 have been labouring under a misapprehension as to this species 

 which he has defined with much care and minuteness in the 

 Manual of Conchology by Tryon and Pilsbry, Vol. xiv. p. 88, 

 pi. XXII, figs. 67-73. 



The true /. longicymha is a New Zealand species and is claimed 

 to be found in South Australia, Tasmania, and Victoria, but so far, 

 I think, no published account has been made of the results of a 

 critical examination of the supposed species otherwise than from 

 New Zealand. 



The '■ scales of the girdle of lladdoni are beautifully regular in 

 size and arrangement and are evenly and deeply grooved ; whereas 

 in loyiyicymba the girdle is closely covered with solid convex but 

 somewhat flattened imbricating scales, most of which are rather 

 weakly striated, but among which non-striated scales are mingled" 

 (Pilsbry). 



