BEDKALL : SOUTH ATJSTEALIAN CHITOIVS. 157 



since made a careful microscopic examination of the species in order 

 to ascertain its true generic position, and the following are his notes : — 

 "Anterior valve has five broad ribs, and the insertion plate is one- 

 third as long as the front slope, carrying five deep slits ; central 

 valves 1-1 ; posterior insertion plates short, with five oblique slits. 

 Sinus wide, square, and very porous. Girdle narrow, corneous, 

 densely covered with minute hyaline spicules, fringed with longer 

 spicules on the edge. Sutural tufts of long horn-coloured spiculse 

 at valve sutures, seven on each side ; four tufts on anterior valve 

 alternately with ribs. There are two colour varieties of this species — 

 one being creamy white, having the side slopes mottled with olive 

 green, and a brown streak along the I'idge from valves 1-7 ; the other 

 variety is dark brown or black with whitish markings. Distinct from 

 Hanleya by reason of slits and insertion plates, and from Angana 

 by the presence of slits in insertion plates of posterior valve, and girdle 

 carrying minute spicuke, not scales." Length 15, breadth 8 mm. 



Hah. — (Type) Yorke Peninsula (Angas) ; Southern Yorke Peninsula 

 (E. H. Matthews) ; Rapid Bay, Kangaroo Island (Betlnall). 



37. Ceyptoplax steiatus (Lamk.), var. Gunnii. 



ChitoneUns Gicniiii, Reeve : Conch. Icon., sp. 5. 



Cryptoplax stn'atiis var. Gunnii, Pilsbry : Man. Conch., ser. I, 

 vol. XV, p. 54, pi. 'siii, fig. 14. 



This variety of Lamarck's Chiton striatus is exceedingly plentiful 

 at all suitable localities on the South Anstralian coast-line, and 

 attains a very large size. It also occurs in Tasmania. 



SPECIES WHOSE OCCUERENCE IS DOUBTFUL. 

 38. IscHNocHiTON Adelaidensis (Recvc). 



Chiton Adelaidensis, Reeve: Coneli. Icon., sp. 123; Smith, Zoology 



H.MS. "Alert," p. 79. 

 Ischnochiton Adelaidensis, Reeve : Pilsbry, Man. Conch., ser. I, vol. xiv, 



p. 136, pi. xxiv, figs. 7, 8. 



Mr. W. H. Harvey, in the early days of the colonization of South 

 Australia (1854-6), collected many natural-histoiy specimens, which 

 he transmitted to England, and presiimably amongst them the present 

 species. Reeve describing it three or four years later as from Port 

 Adelaide. The opinion of Messrs. E. A. Smith and H. A. Pilsbry, 

 however, is that, as with many other specimens in the Cumingian Col- 

 lection, the labels had become mixed. The discovery in the early part 

 of 1895 of a closely allied shell at several stations on the east side of 

 St. Vincent's Gulf, induced me to communicate with Mr. Smith, and to 

 suggest that the specimens, which I could not satisfactorily separate 

 from /. smaragdinus, Angas, might possibly be /. Adelaidensis, and 

 in that event the two species were probably identical. Mr. Smith 

 identified my specimens, however, as /. smaragdinus; consequently Ave 

 still need evidence that /. Adelaidensis is a denizen of South Australian 

 waters. 



