140 HELCIONISCUS. 



Mar. Moll. N. Z. p. 45 (1873), not of Q. & GLottia radians Sow- 

 ERBY (de novo\ Genera, Lottia f. 3. Patella affinis REEVE, Conch. 

 Icon. f. 108, (1855.) P.fusca LINN., Syst. Nat. x, p. 784. HANLEY, 

 Shells of Linn., p. 428, t. 4, f. 9 (fig. of Linnaeus' type specimen). 

 P. sagittata DONOVAN, Rees' Encyclop., Conchol. t. xvi. 



The earliest name proposed for this shell is that of Linne, P.fusca. 

 It was defined in an absurdly inadequate manner, however, and as 

 Hanley justly remarks, no claims to precedence can be grounded 

 upon the mere preservation of the original specimens. 



Typically depressed, but sometimes as elevated as P. redimieulum. 

 The sculpture of narrow separated riblets, having in the intervals a 

 smaller riblet, or numerous minute riblets (sometimes obsolete), is 

 characteristic. Sometimes the whole surface between the larger 

 ribs is finely granulose, and most specimens retain this granulation 

 in front of the apex. 



The connecting forms are so numerous that I am unable to 

 diagnose any of the following as varieties worth naming. 



Typical form (pi. 69 figs. 25-28). Much depressed, thin, riblets 

 often subobsolete ; conspicuously striped and blotched with brown or 

 red on a bluish-white ground, yellow around the apex. 



The form called argentea by Q. & G. is dark, mostly olivaceous, 

 depressed. 



The P. decora of Philippi (pi. 69, figs. 29-31) is yellowish with 

 about 24 narrow, reddish-brown ribs, alternating with small riblets. 

 Reeve's decora is intermediate between this and argentea Q. 



Reeve's P. ear Hi (pi. 21, figs. 51, 52) is typically more elevated, 

 rounder, " pale green, broadly wave-variegated with olive-black." 

 It is very closely connected by intervening forms with the type. 



The P. affinis of Reeve (pi. 69, figs. 32, 33) scarcely differs from 

 the typical radians. " The surface is carved throughout with simple 

 smooth, slightly waved, close-set ridges and striae." 



Var. PHOLIDOTA Lesson. PI. 69, figs. 38, 39. 



Ribs small and uniform ; apex very anterior, about one-seventh 

 of the length from the anterior end. Olive-brown, largely blotched 

 with white, or white with brown radiating bands. (Hutton.~) 



Throughout New Zealand. 



P.pholidota LESSON, Voy. de la Coquille, p. 420 (1830). P. 

 sturnus HOMBR. & JACQ., Ann. des Sci. Nat. (2), xvi, p. 191, (1841). 



