Ischnochiton.\ AMPHINEURA. 11 



Remarks. To judge from the valves gathered, the species will 

 attain a slightly larger size, but most of my specimens are considerably 

 smaller. The colour, smallness, and absence of radiating sculpture 

 distinguish this species. It belongs to the group with smooth scales. 

 A specimen from Dusky Sound is yellowish-white, mottled with brown 

 triangular streaks and spots, crowded along the ridge, but otherwise 

 it does not differ from Bounty Island specimens. 



5. Ischnochiton Parkeri, Suter, 1897. Plate 3, fig. 5, a-d. 



Isch)wr.hiton Parkeri, Suter, P. Mai. S., ii, 186, f. 1-6 in text. Lepidopleurus 

 circumvallatus, Reeve: Hutton, M.N.Z.M., 113, not of Reeve. 



Shell oblong, angularly arched, yellowish to brown, lateral areas 

 with feeble radial riblets. Anterior valve minutely decussate, with 

 numerous radiate low riblets, which are more or less cut up into fine 

 nodules by concentric growth-lines. Intermediate, valves angularly 

 arched, beaked, the sutures distantly serrate, jugum and central areas 

 finely granulated by longitudinal and transverse zigzag wrinkles ; 

 lateral areas raised, with numerous broad, flatly rounded, concentric 

 ridges, the interspaces faintly granulate; sometimes distinct radiate 

 riblets, numbering 8-10, are present. Posterior valve with the central 

 area finely granulate, posterior area with numerous unequal and 

 rounded concentric ridges ; mucro central, low and obtuse, posterior 

 slope slightly concave. Girdle covered by small imbricating scales, 

 which are all of about the same size, convex, deeply grooved, 3- grooves 

 on each ; margin of girdle with a fringe of minute spicules. Colour 

 variable, from horny-yellow to chestnut-brown, mostly darker on the 

 posterior margin of the valves, with more or less predominant black 

 longitudinal stripes, assuming often a triangular shape, closer together 

 or coalescing towards the girdle, jugum mostly without black mark- 

 ings. Interior blue ; anterior valve with 11-13 slits, intermediate 

 valves with 1 slit on each side, posterior valve with 12-13 slits ; teeth 

 sharp and smooth, posterior tooth of intermediate valves short, as 

 in /. longicymba ; sinus broad and smooth ; the sutural laminae rather 

 low, broadly rounded ; valve-callus stout. 



Length, 21 mm. ; breadth, 12 mm. Divergence, 110-120. 



Type, from Campbell Island, in the Otago Museum, Dunedin. 



Hob. Campbell Island ; Auckland Islands ; Bare Island (Schauins- 

 land). 



Remarks. It is no doubt this species which was taken for 1. lonyi- 

 cymba, Q. & G., by Filhol and Hutton. According to Thiele, it is 

 /. melanterus, Rochebrune. 



Subfam. 2. CALLOCHITONIN.E. 

 With shell-eyes and united sutural laminae. 



