LEPIDOPLEURUS. 13 



entiated areas. Middle valves with short but high sutural plates ; 

 no insertion plates ; sinus large and deep ; the division of the central 

 and lateral areas is marked inside by a slight groove. The front 

 margin of the anterior valve is semicircular, the posterior margins 

 meeting at an angle of 150. The posterior margin of the posterior 

 valve is about the third of a circle, its front margin is seen from 

 above as a straight line. The mucro is subcentral, somewhat more 

 forward than behind. 



The color of the valves is a pale gray-brown, irregularly covered 

 with brown dots which are lacking at the margins, leaving there 

 a paler, unicolored zone. The girdle is brownish, the scales White. 

 The length cannot be given exactly, as all the specimens were 

 strongly rolled up ; but the maximum length seemed to be 4*7, 

 breadth of the shell 2'5 of the girdle 0'8 mill. (P/r.~). 



South Georgia. 



Leptochiton pagenstecheri PFFR., Jahrb. Hamburg. Wissen- 

 schaftlichen Anstalten, iii Jahrgang, p. 107, t. 3, f. 3, 1886. 



L. AHELLUS Spengler. PI. 3, figs. 64, 65, 66. 



Shell small, rather elevated, the dorsal ridge bluntly angular. 

 Very minutely and evenly, but rather indistinctly, lirate-granulate; 

 olive-ashen, often having longitudinal delicate pencilings of olive- 

 green. 



Anterior valve very densely, minutely and evenly granulated, 

 the granules being irregularly, but usually visibly, arranged in radi- 

 ating rows ; the peripheral third of the valve having coarse concen- 

 tric wrinkles. 



Intermediate valves have the central areas finely densely longi- 

 tudinally granose-lirate. Lateral areas closely granose, the granules 

 arranged in radiating rows on the lower portions, which are also 

 wrinkled like the anterior and posterior valves. The lateral areas 

 are separated from the central area by an inconspicuous low ridge. 



Posterior valve with subcentral, rather low umbo, the posterior 

 slope concave. Interior of valves white ; sutural plates small. 



Lojoten Is., Norway, Iceland and Greenland, south to Gulf of 

 Gascony. 



Chiton asellus SPENGLER, Skriv. Nat. Selsk. 1797, vol. iv, p. 99. 

 LOWE, Zool. Journ. ii, p. 101, t. 5, f. 3, 4, 1825. BROWN; 

 DESHAYES in LAMARCK An. s. Vert. ; MIDDENDORFF ; FORBES & 

 HANLEY, Brit. Moll. vol. ii, p. 407, t. 59, f. 1, 2. Chiton minimus 

 CHEMNITZ; WOOD; DILLWYN. Chiton cinereus MONTAGU; 



