576 THE VOYAGE OF H.M.S. CHALLENGER. 



The Litorina affinis, d'Orb., is the young shell of this species. The earlier whorls are always 

 more or less nodulous, and even in the full-grown shell one often finds traces of tubercles supplying 

 links between the nodose and the smooth forms ; while at the same time the action of the surf often 

 effaces the tubercles which had actually existed on the upper whorls. Facts of this sort are palpable 

 to a collector who gathers on the beach, and knows the mollusks in the conditions of their actual 

 life, but are apt to escape a museum systematist, who despises young and poor specimens, and 

 " pitches away," as the phrase goes, inconvenient and troublesome forms, which for real study are the 

 most valuable of all. The classification of these tubercled forms under Hamus as distinct species, 

 is an indication of the worthlessness of such subdivisions. 



7. Litorina (Hamus) montrouzieri (Fischer). 



Tedaria montrouzieri, Fischer, Joum. de conch., vol. xxvi. (1878) p. 212; vol. xxvii. (1879) p. 31, 



pi. iii. fig. 6. 

 Litorina (Tectaria) montrouzieri, Weinkauff, Conch. Cab. (ed. Kuster), p. 102, No. 118, pi. xiv. 



figs. 14, 15. 



September 8, 1874. Flinders Passage, Cape York, North Australia. 7 fathoms. 

 Habitat. — New Caledonia (Fischer). 



Is this species really distinct from Litorina papillosa, Lam. ? It is thinner, the whorls overhang 

 the suture more, and the base is not tubercled ; but that species is so variable that these, doubtful 

 specific features in the whole genus, are more than usually questionable here. 



8. Litorina (Hamus) granulans, Gray. 



Litorina granularis, Gray, ZooL Beechey's Voy., p. 140. 



„ „ Philippi, Abb. und Besch, vol. iii. p. 63, sp. 5, pi. xv. (Gen. vii.) fig. 7. 



„ „ Reeve, Conch. Icon., vol. x. pi. xiii. fig. 68. 



„ nodosa (not of Gray), Reeve, Conch. Icon., voL x. pi. ii. fig. 13. 



„ exigua, Dunker, Malak Blatter, vol. vi. p. 226. 



Dunker, Moll. Jap., p. 13, pi. ii. fig. 3. 



Lischke, Jap. Meereseonch., vol. ii. p. 70 



Weinkauff, Conch Cab. (ed. Kuster), p. 95, pi. xiii. figs. 13, 16. 



Dunker, Index Moll. Mar. Japon., p. 111. 



May 14, 1875 



Oosima, Japan. 



Habitat. — ? (Gray) ; New Zealand (Philippi). 



I have no doubt that the Challenger specimens belong to this species of Gray. Having that 

 conviction, I feel that I have the authority of Lischke for quoting Litorina exigua, Dunker, as a 

 synonym, a fact which Lischke himself denied ; for, while identifying Litorina exigua, Dunker, with 

 Litorina granularis, Reeve, he denied that Reeve's species was that of Gray or of Philippi (loc. 

 cit. supra). His reason for this opinion is that in some points the descriptions do not tally : 

 notably, that Gray gives for the size seven lines instead of seven millimetres ; but chiefly, and 



