CHITON. 181 



ROCHEBR., Nouv. Arch, du Mus. 1881, p. 242. Chiton polii DESK. 

 (not Phil.)., Exped. Sci. de Moree, iii, p. 132 ; Lamk. edit. Dh., vii, 

 p. 504. C. squammulosus DOLLFUS, Catal. Palavas, p. 3. 



Doubtful synonyms : Lophyrus siculus forma africana ROCHE- 

 BRUNE Journ. de Conchyl. (3) xxi, p. 42 (1881). Chiton striatus 

 CHIEREGHINI MS. BRUSINA Ipsa Chier. Conchyl. p. 44 (1870). 

 Ch. estuarii CHIER., MS. BRUS., /. c., p. 45. 



This common Mediterranean species is very variable in color, as 

 the figures show, but quite constant in sculpture. The valves are 

 generally very much elevated, like a gothic roof. The prominence 

 of the mucro or beak of the tail-valve, and its central position, are 

 characters showing the strong bond of affinity between olivaceus and 

 the Australasian species, and sundering it from the somewhat 

 similarly sculptured West Indian forms. Issel and the authors of 

 Mollusques Marins du 'Roussillon classify the color-forms of this 

 species into two groups : (1) those which are variously marbled and 

 spotted, and (2) those which are unicolored, forming the 



Color-var. unicolor Issel. Entirely white, tawny or red. It is 

 likely that C. rubellus of Nardo was founded upon an individual of 

 the last color. 



I regard it as probable that the Lepidopleurus corallinus of Risso 

 (Hist. Nat. PEur. Merid. iv, p. 268) was based upon a red example 

 of C. olivaceus. Monterosato has suggested that corallinus is the 

 same as rubicundus Costa,-\-scytodesma Sc&c.,-{-freelandi Fbs.-(- 

 pulcliellus Phi\.-\-philippii Issel (see Journ. de Conch. 1878, p. 146). 

 This identification seems to me to be quite inadmissible. 



Rochebrune describes a ' forma ' Africana as follows : Allied to 

 L. siculus, but differs in having the valves obtusely carinated, the 

 sulci of the central areas very delicate, straight. Length 26 mill. 

 Promontory of Cape Verde, and Table Bay, Cape of Good Hope. 



The reference of this form to the present species is doubtful. 



C. AFFINIS Issel. PI. 35, fig. 93 (enlarged.) 



Shell oblong, subcarinated, smooth, painted with various colors ; 

 end valves radiately ribbed, the front valve having about 21 ribs, 

 concentrically striated ; the other valves having longitudinal 

 arcuate grooves ; lateral areas narrow, triangular, transversely tri- 

 sulcate. Girdle minutely scaly. 



Length 18, breadth 11, alt. 6 mill. (Issel.) 



. Gulf of Suez. 



