ISCHNOCHITON. 99 



SOWB., Conch. Illustr. f. 61 (not described, and referred by Sowerby 

 to textilis). Not Ch. textilis of Reeve, Conch. Icon. f. 91. 



The above description is from Gray's Spicilegia, the more impor- 

 tant passages being italicised by me. Gray's figure is absolutely 

 worthless. Reeve's figure and description do not pertain to this 

 species, but to I. (Radfdella) zebra Krauss. The true 1. textilis is 

 in all respects a typical Ischnochiton. I refer the imdescribed (7. 

 solea of Sowerby to textilis because it is said to be that species by 

 Sowerby himself; but the figure is very poor. The details herein 

 given will enable students to identify Gray's species with compara- 

 ative ease and certainty, without a figure ; for it seems to be closely 

 allied to the J. oniscus only among South African Chitons. The 

 details of sculpture of the central areas and the coloring seem to be 

 especially characteristic. Krauss describes specimens collected by 

 him, and which he at one time considered a new species which he 

 intended naming C. ludwigi. His description is as follows : 



Shell ovate-elongate, semipellucid, subcarinated ; white in the 

 middle, the sides ashen-green, often spotted with brown ; interior 

 white. Front valve lunate, tail valve rather depressed, submucro- 

 nate in the middle ; intermediate valves having the central areas 

 finely punctate on the ridge, longitudinally striolate at the sides ; 

 lateral areas and end valves radiately rugulose-striated. Girdle 

 ashen, submaculated, scaly, the scales small and oblong, excessively 

 finely multicar mated. Length 22, breadth 11 mill. Table Bay. 



The anterior valve and the posterior part of the posterior valve 

 are radially wrinkle-striated and have 12 slits in the insertion 

 plates, which are smooth and shorter than the eaves. The median 

 valves are rather narrow (8'6 x 3 mill.) and have distinct lateral 

 areas with 5 to 6 strong wrinkle-like and interrupted striae. The cen- 

 tral areas are seen under a lens to be covered with fine raised points, 

 which toward the margins become more and more distinct, and 

 near the lateral margins as well as in front of the lateral areas they 

 unite into distinct longitudinal rows. The sutural plates are 

 rounded ; insertion plates short, smooth, and having a single slit. 

 The girdle is covered with extremely small, thin longitudinal scales, 

 not discernable to the naked eye, and prettily marked with 8-9 

 stride. The color is whitish in the middle of the shell, grayish - 

 green on the sides, and dotted and flecked throughout with brown. 



Krauss also describes the following: *. 



