284 NUTTALLINA. 



Ch. polii PHILIPPI, Enum. Moll. Sicil. i, p. 106 (1836) ; ii, p. 83 

 (1844), and of most subsequent authors ; not Ch. polii Desh. 1832. 

 Ch. crenulatus LoOARD, Coq. Mar. des Cote's de France, p. 233. 

 (1892), and perhaps C. crenulatus Risso Eur. Merid. p. 267. Chiton 

 decipiens TIBERI, Bull. Soc. Mai. Ital. iii, p. 141 (1877). Chiton 

 corrugatus REEVE Conch. Icon., t. 28, f. 185 (1848). 



Distinguished from other Mediterranean species by the finely 

 granose- scaly sculpture covering the entire surface, with two low 

 ribs at the lateral areas and 8 or 9 on the head-valve. The girdle 

 is composed of short striated scales crowded together, producing a 

 " cobble-stone pavement " surface. The true nature of the scales 

 appears only when highly magnified. The nomenclature of the 

 species is peculiarly involved, like that of most Mediterranean Chi- 

 tons. Poli believed it to be the cinereus of Linnaeus, but Philippi dis- 

 tinguished it from that and gave the name Polii, which unfor- 

 tunately had been some years before bestowed by Deshayes upon 

 another species. Monterosato claims to have identified it with Ch. 

 caprearum (" caprearm ") of Scacchi, by examination of a type in 

 the Petit collection ; but the description given by Scacchi is 

 inadequate. Scacchi says : " Chiton caprearm [sic] Nobis. Clypeis 

 8 tuberculatis virescentibus, fascia marginali squamoso-muricata, 

 perbelle ciliata. Longus lin. 6, latus lin. 4i. Caprearum scopulos 

 incolit. " Locard identifies it with crenulatus Risso, the original 

 description of which follows : " C. crenulatus. Dorso segmentis omni- 

 bus cinereis crenulatis, Long. 17 mill. Penn. Br. Zool. 4, XXX VI, 

 3, Pol., 4, iii, f " Of course this may be the present species, but the 

 wretched description, without a figure is quite unacceptable. Tiberi 

 proposed the name Ch. decipiens as a substitute for polii Phil, not 

 Desh. The locality of Reeve's Ch. corrugatus is not known, but the 

 description and figures render its identity reasonably certain, and 

 Carpenter declares the types to be young polii Ph. In the midst of 

 so many conflicting names and opinions I prefer to retain the name 

 given by Poli. His description is infinitely better than any of the 

 later ones mentioned above. Indeed Poli's work upon this species is 

 wonderful for his time, and with such an example before them it is 

 surprising that so many Mediterranean naturalists have left such 

 miserable work. 



It is needless to say that the Chiton cinereus of Linne belongs to a 

 genus which must be admitted by all naturalists who examine the 

 subject, to be perfectly distinct. 



