95 



thousand miles of coastline, but going out from Murat Bay 

 to St. Francis Island (Nuyts Archipelago), a distance of 

 40 miles, Plaxiphora costata, Blain, formerly known as P. 

 glauca, Q. et G., takes the place of P. albida, and specimens 

 of P. costata were found in Western Australian waters. P. 

 albida, Blain., is generally found on or above high-water 

 mark in South Australia, but on the Western Australian 

 coast its place is taken by Liolophura georgiana, Q. et G. 

 These could be frequently seen on exposed rocks. The order 

 of exposure in South Australian waters, mutatis mutandis, 

 is P. albida, on exposed rocks at or near high- water mark ; 

 I. crispus, in abundance everywhere, in sheltered pools, a 

 foot or two below, with Acanthochites on sandy moss-covered 

 rocks. In deeper pools, I. contractus, I. cariosus, I. ustu- 

 latus, 1. smaraydinus, and other Ischnochitoniclce, and deeper 

 still in 2 or 3 ft. of water at low tide, the true chitons, 

 Jugosus, tricostalis, exoptandus, and calliozona. On the west 

 side of St. Vincent's Gulf I have found the true chitons on 

 exposed rocks in shallow pools. 



The order in which Western Australian chitons are found 

 is Liolophura georgiana, near or above high- water mark (P. 

 albida and /. crispus are missing), and on account of the 

 small fall of the tides Chitons, Callochitons, and I schno chitons 

 may be found together. The Ischnochitonidce favour shallow 

 pools, while the true chitons prefer the ocean surf. 



Chiton torrianus was found in Western Australia on the 

 under-side of wholly exposed rocks. This chiton, formerly 

 misnamed coxi, was separated by Hedley and Hull as C. 

 torri, afterwards altered to torrianus. It was rarely found 

 in South Australian waters till Mr. Walter Klem, of Corney 

 Point, Yorke Peninsula, discovered a number. In Western 

 Australia it was found in almost every place visited. 



It is hoped that this first paper on Western Australian 

 Polyplacophora may do something fto stimulate and help 

 future beginners at chiton-hunting in Western Australia. 



My acknowledgments are due to Mr. W. T. Bednall, 

 whose excellent paper on South Australian Polyplacophora, 

 Proc. Mai. Soc, London, vol. ii., part iv., April, 1897, has 

 been the foundation of much of my work, and to whose 

 paper I have had frequently to refer; also to Mr. M. M. 

 Maughan, B.A., for his kindly revision of my paper and his 

 assistance in examining my new species and verifying some 

 of my descriptions. 



1. Callochiton platessa, Gould, 1846. 



Chiton platessa, Gould, Proc. Bost. Soc, N.H. II., 1846, 

 p. 143; Pilsbry, Man. Conch., ser. i., vol. xiv., p. 49. 



