ISCHNOCHITON. 79 



Carpenter's notes are as follows : Five specimens, no localities, 

 Mus. (Juming. A very remarkable species, with a very singular 

 combination of characters. Perhaps it belongs rather with gemmea, 

 etc. Valves rather pointed in front, and broader behind ; shell 

 oval, somewhat elevated, jugum rather sharp. Green, with one or 

 more valves always variegated with darker; fine tessellations at 

 sutures, causing it to appear toothed. Mucro rather raised at 

 anterior third ; posterior slope very concave. Valves rather curved, 

 with conspicuous, rather obtuse apices. Side areas scarcely distinct. 

 The whole surface is rather glossy, but under the microscope with 

 extremely fine granulation, which runs into fine lines along and 

 near the jugum. Girdle Trachydermoid, covered with extremely 

 minute scales and occasional hairlets, but at the sutures and in a 

 row around the margin are a series of brown dots which turn out 

 to be semi-pores, quite regular but without hairs, only larger grains 

 making a kind of knob. They are very conspicuous as pore-lumps 

 when the shell has been soaked. The anterior valve has 11, central 

 1, posterior 9 slits. Teeth stumpy, like nuttallii, but not striated. 

 Sinus shallow and rounded, with about 16 teeth, formed by the 

 lirations of the anterior part within. Eaves short and very spongy. 



Length 12i, breadth 7 mill.; divergence 113. 



I. STRAMINEUS Sowerby. PL 8, fig. 71. 



Shell ovate, smooth, pale straw-colored ; back rounded ; marginal 

 scales sparse. (Soivb.) Length 10, breadth 6 mill. 



Island of Chiloe, under stones at low water. 



Chiton stramineus SOWB., P. Z. S. 1832, p. 104 ; Conchol. Illustr. 

 f. 28; Zool. Beechey's Voyage, p. 150, t. 41, f. 13. Trachydermon 

 stramineus Sowb., CARPENTER, MS. p. 21. 



Carpenter remarks : A distinct species. Five specimens in Mus. 

 Cuming, much worn and smashed. They scarcely show the sculpt- 

 ure ; in the best there is an attempt at granulation. Rather broad, 

 flat, rounded jugum. Girdle gravelly; mucro median, a trifle 

 raised ; posterior slope nearly straight. The anterior valve has 15, 

 median 1, posterior 10 slits; teeth sharp, Ischnoid; eaves moderate. 

 Length 11J, breadth 7 mill.; divergence about 114, the valves 

 rounded. 



