i IIM.X.H m i 



<(' a dense, porcellanuu> texture. The laciniated inMltk>n*p] 

 cut into many short teeth, combined with the haohh mile 



and continuous sut ural-plate>, an- the nio>t >t rikinir L r eiierir diar- 



acten, 



From A<'<inflx>}>/i urn and Mau^i-rin, irroups to which Home 

 authors have referred the type of this ircnus, Kml<,.n,rliifoi, is 

 sundered by the lack of eyes in the valves, the multiplicity of .-lit-, 

 dcpres-cd inucro, etc. 



I', sides the following, C/i. /inter (CLem.) Reeve may belong to 

 this genus, but its generic characters are entirely unknown. See 

 appendix. 



I-:. eroBiua (Jray. PL 46, figs. 88-95. 



Shell ohlon.ir, < /< r<itr<l, the valves well arched, and very obtusely 

 angular on the dorsal ridge, side-slopes convex. Color uniform dark 

 brown, a little mottled toward the beaks, and marked with scarlet 

 there ; girdle rusty-brown. 



Valves broadly A-shaped, not beaked, the lateral areas moder- 

 ately raised, smooth except for the microscopic granulation and a 

 few excessively indistinct radii. Central areas having indistinct 

 growth-lines. Posterior valve (figs. 92, Q3, 94) elevated in front, the 

 mucro flat, central ; posterior margin gently emarginate behind. 



Interior porcelain-white, immaculate ; smooth and poreless. 

 Sutural plates squared, continuous across the sinus, which is indicated 

 by a median bay or notch. Insertion-plates having broad, blunt 

 edges, irregularly and deeply pectinated, and having in the head- 

 valve 30, median valves 3-4, tail- valve 24-25 short slits. Eaves 

 very narrow, deeply grooved along the teeth and slightly spongy 

 there. 



(iirdlc(fig. 95) leathery, rust-colored, bearing short rigid bl<n-k 

 spinelets. Length 60, breadth 35 mill. ; divergence 100-110. 

 , Cnvk*' Sfntif ; Martin'* Jinii. X* 



Acctnthqpleura >/oA///V ( ii; \v. in Dieffenbach's New Zealand, ii, p 



i 1843). Chiton (Einlu-nrl,it,m') m>/n'li* Gray, SHUTTLW.. l>orn. 



Mittheil. 1*.~)3, p. 67. Chitn,, t Ch&tcpleura) iinbili* (\\-\\\, SMITH, 



Zool. Erebus and Terror, p. 4, t. 1, f. 8 (1874 >. HuTTON, Man. N. 



/. Moll., p. 115 (1880.) 



This species differs from the following in its more elongated and 



much more elevated contour, and in the stronger valves. The 

 13 



