426 ON THE OCCURRENCE OF PLECOTREMA, ETC., IN PORT JACKSON, 



The species piceus is omitted in Whitelegge's List of the Inver- 

 tebrate Fauna of Port Jackson, published in the Journal and 

 Proceedings of the Royal Society of N. S. Wales for 1889, and 

 Chiton incayia of Gould represents the species there, No. 652, 

 p. 273 ; but as the latter is a synonym of Liolopleura Gaimardi of 

 Blainville, the name incana will not stand. 



Under any circumstances the name piceus must be given up for 

 our Liolopleura, and it must be given up also for our Acanthopleura, 

 for a species of each of these genera exists in Port Jackson and on 

 our adjacent coasts ; one is Liolopleura Gaimardi, Blainville, the 

 other is Acanthopleura spiniger, Sowb. 



The former occupies exposed surfaces of rocks about high-water 

 mark, and prefers fretted-out holes in the rock ; the other I have 

 only obtained by wading at very low tides, and then it is generally 

 under rocks or in secluded places. The two species are extremely 

 alike, but A. spiniger is the larger of the two ; the two species 

 can be readily distinguished by the characters of the girdle spines, 

 spiniger having calcareous black or buff smooth spines, rather 

 regularly curved, in alternate light and dark patches, about 

 21 mm. long, the interior of the valves of a purple-brown 

 colour ; Gaimardi has the girdle densely clothed with inter- 

 mingled minute, larger, and large calcareous spines, white and 

 dark in alternate patches, some of them being striated. 



For general details, see Tryon and Pilsbry's Man. of Conch. 

 Yol. xiv. pp. 221 and 240. 



Chiton glaucus. Gray. 



This name is given in Angas's List of the Species of Marine 

 MoUusca found in Port Jackson and the adjacent Coasts, published 

 in P.Z.S. for 1867, p. 185, No. 229. He gives as synonyms for 

 the species, Ch. Quoyi, Desh., and Ch. viridis, Q. et G. He 

 remarks that it is rare in Port Jackson, very variable in colour, 

 and that the green var. is Ch. Quoyi. 



The only other list of any importance of Port Jackson shells 

 published is by Whitelegge, in the Journ. and Proc. of the Royal 

 Soc. of N. S. Wales for 1889, where the same supposed species is 



