151 



Very often found covered with calcareous matter. I 

 have traced it from Port MacDonnell through both gulfs to 

 St. Francis Island. Some beautiful dark-brown specimens 

 came from Mr. Anderson, of Second Valley, and rich red 

 (iron-stained ?) ones from Cape Jaffa. Its sculpture and 

 rounded appearance easily differentiates it from other chitons. 

 It is our only South Australian Callistochiton. "This genus 

 differs from Ischnochiton in the peculiar insertion-teeth, 

 which are curved into ribs as if festooned, in the relation of 

 the slits to the external ribs, and in the tail valve, which is 

 often peculiarly humped" (Pilsbry, Man. Conch., ser. i., vol. 

 xiv., p. 260). This chiton has a very wide range, and has 

 been collected by the author in places as far apart as Queens- 

 land and Western Australia. 



Fam. CHITONLDI^E, Pilsbry. 



25. Onithochiton ashbyi, Bednall and Matthews, 1906. 



Onithochiton ashbyi, Bednall and Matthews, Proc. Mai. Soc, 

 London, vol. vii., part 2, June, 1906, p. 92. 



As far as I am aware, only one specimen of this chiton 

 has been discovered. It was found by Mr. Ashby at Aldinga, 

 and to him I am indebted for the specimen. It is our only 

 Onithochiton, and the eyes are of a pearly appearance set in 

 its cream-coloured valves. The smooth warty appearance will 

 easily distinguish this shell. 



26. Chiton tricostalis, PiJsbry, 1894. 



Chiton ( canaliculatus , var. ?) tricostalis, Pilsbry : Nautilus, 

 vol. viii., 1894, p. 54. 



C. tricostalis, Pilsbry: Bednall, Proc. Mai. Soc, London, 

 vol. ii., part 4, April, 1897. 



This "handsomely sculptured shell" assumes an endless 

 variety of colour. I have specimens, red and green, pink and 

 black, green and white, creamy, cream with black spots, 

 yellow with black spots, etc. The second valve is often of a 

 distinctive colour. It is bicostalis in small specimens, the 

 middle rib in the lateral areas begins when about half -grown. 

 Some valves have four ribs. I have specimens from Capes 

 Jaffa and Jervis, several places in Gulf St. Vincent, Southern 

 Yorke Peninsula, and St. Francis Island. I have collected 

 it in Western Australia, and have specimens from New South 

 Wales. 



27. Chiton calliozona, Pilsbry, 1894. 



Chiton (Mrcus, var.) calliozona, Pilsbry : Nautilus, vol. viii., 

 1894, p. 55. 



C. calliozona, Pilsbry: Bednall, Proc. Mai. Soc, London., 

 vol. ii., part 4, April, 1897, p. 151. 



