Helcioniscus.] GASTROPODA. 79 



B. Ribs distinctly granular. 



a. Ribs 22-30, scale-granose ; apex at anterior fourth ; 



spatula orange-brown . . . . . . . . denticulatus. 



b. Ribs crenulate to granose. about 40 principal ribs, 1 in- 



terstitial riblet, with radiate black stripes ; apex in 

 front of centre ; interior with dark rays and spots ; 

 spatula yellow to brown . . . . . . . . antipodum. 



c. Ribs granular ; colour reddish to black, white radiating 



rays form a star or extend to margin . . . . stelliferus. 



d. Ribs coarsely nodular ; apex at anterior third ; inter- 



mediate riblets sometimes dotted with black and 



white ; interior brown, with 1112 white rays . . ornatus. 



e. Shell small, subpellucid ; 24-30 granular ribs ; blackish- 



brown or yellowish-grey, and ribs alternately black 

 or uniformly flesh-coloTir ; apex at anterior third. 

 Kermadec Islands only . . . . . . . . craticulatus. 



1. Helcioniscus antipodum, E. A". Smith, 1874. Plate 7, fig. 9. 



Patella antipodum, E. A. Smith, Ereb. & Ter., Moll, 1874, 4, pi. 1, f. 25. 

 P. tramoserica of authors, not of Martyn, 1784 ; Pritchard and Gatliff, 

 P.R.S. Vic. (n.s.), xv, 191. Helcioniscus diemenensis, Philippi : Gatliff 

 and Gabriel, op. cit. (n.s.), xxi, 382. 



Shell rotundately ovate, a little narrowed in front ; the apex much 

 inclined anteriorly, placed at a distance of one-fourth of the entire 

 length from the front margin ; radiately rather finely ribbed, ribs 

 crossed by the fine concentric lines of growth ; orange-yellow, clouded 

 with white around the middle, varied with 10 or 11 black narrow 

 rays placed at nearly equal distances, those in front being rather 

 more approximated than the rest ; the interior is brilliant pearly 

 orange-yellow, the exterior black rays being visible, especially at the 

 margin, which is finely crenulated. (E. A. Smith.) 



Length, 28 mm. ; width, 22 mm. ; height, 9 mm. Length, 31 mm. ; 

 width, 24 mm. ; height, 16 mm. (Hauraki Gulf specimen). 



Type in the British Museum. 



Hob. New Zealand (Lieut. -Colonel Bolton) ; Hokianga ; Hauraki 

 Gulf (H. S.) ; Wellington and Chatham Islands (fide Button) ; Ker- 

 madec Islands (Haylock). Tasmania and Australia ? 



Remarks. Gatliff and Gabriel state that the Australasian species 

 generally known as P. tramoserica, Martyn, is not the shell figured 

 by Martyn, and that he mentions the north-west coast of America 

 as the habitat of his species ; they therefore adopt the name P. die- 

 menensis, Philippi, 1848. Replying to my inquiry, Dr. W. H. Dall 

 most obligingly informed me that (1) Martyn' s figure, which is 

 good, does positively not represent any north-west American species ; 

 (2) that P. diemenensis is an unfigured and doubtful species ; (3) if 

 bent on changing the name, it would be better to take Patella anti- 

 podum, E. A. Smith, 1874, which is a synomyn of the tramoserica of 

 authors, not Martyn. I follow here Dr. Dall's excellent advice, as in 



