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4. Gena atiricitla Lamarck. 



Lamarck. An. s. vert. Ed. Desh. Vol. IX, p. i-j [Stomatella). 



PiLSBRY. Man. of Conch. Vol. XII, p. 44, PI. 2, figs. 29 — 31 ; PI. 55, figs. S, 9 {lutea). 

 Smith. Marine Mollusca. Fauna and Geography of the Maldive and Laccadive Archipelago, 

 p. 618, N" 271. 



Stat. -^j. Sailus Ketjil, Paternoster-islands. 18 and 27 M. Coral and Coralsand. 3 Spec. 

 Stat. 58. Seba, Savu. Reef. I Spec. 



Stat. 81. Pulu Sebangkatan, Borneo-bank. Reef. \ Spec. 

 Stat. 89. Pulu Kaniungan Ketjil. Reef, i Spec. 



Stat. 93. Pulu Sanguisiapo, Tawi-Tawi-islands. Reef and 12 M. 6 Spec. 

 Stat. 99. North-Ubian. 16 — 23 M. Lithothamnion-bottom. i Spec. 

 Stat. 133. Lirung; Salibabu- island. 36 M. Hard sand, i Spec. 

 •Stat. 213. Pulu Pasi, Tanette. Reef. 2 Spec. 

 Stat. 213. South-island. Reef, i Spec. 

 Stat. 220. Saleyer. Reef, r Spec. 



Stat. 234. Nalahia-bay, Nusa-laut-island. Reef. I Spec. 

 Stat. 240. Banda. 9 — 45 M. Lithothamnion-bottom. 12 Spec. 



Stat. 282. Between Nusa Besi and the N.E. point of Timor. Reef and 27 — 54 M. 3 Spec. 

 Stat. 315. East of Sailus Besar, Paternoster-islands. Up to 36 M. Lithothamnion-bottom. 3 Spec. 



The specimens vary much in colour, but agree in sculpture, consisting of fine spiral 

 striae on the upper whorls and a few near the basal or left margin, and very fine radiating 

 striae on the last whorl, being more conspicuous towards the right margin. 



The colour varies from carmine to white and even blackish, with more or less numerous 

 white spots and often darker, articulated, spiral bands. The upper whorls are commonly of 

 another colour than the bodywhorl. The nomenclature is far from clear; Lamarck cites Rumph, 

 PL 40, fig. I, as belonging to his Stomatella atcricula, which is certainly erroneous; Pilsbry seems 

 to have in view this species for his G. lutea Linn., though he agrees with Hanley's opinion 

 that Patella lutea of Linn£ is unidentifiable, he believes that it is the G. lutea of Adams. I have 

 followed the advice of Mr. E. A. Smith, in accordance with the specimens of the British Museum. 



In the animal the siphons and epipodial cirri are present, so it does not differ materially 

 from G. plamilata. Some specimens have lost their tails, even a few seem to have shed it off 

 after being placed in alcohol, at least I found loose tails. The teeth of the radula agree in 

 most respects with the description and figure of teeth of G. lutea by Thiele (Troschel, Gebiss 

 der Schnecken, Vol. II, p. 263, PI. XXV, fig. 25) only the number of the smaller cusps of each 

 tooth is slightly different, so 1 find only two denticles at the external or fifth lateral, instead 

 of 3 ; this seems however to be of little importance for specific distinction. 



5. Gena ornata A. Adams. 



A. Adams. Proc. Zool. Soc. Lond. 1850, p. 39. 



Reeve. Conch. Ic. Vol. XIX, Gena, fig. 9. 



Pilsbry. Man. of Conch. Vol. XII, p. 45, Pi. 55, figs. 29, 30. 



Stat. 282. Between Nusa Besi and the N.E. point of Timor. 27 — 54 M. Sand, coral and 

 Lithothamnion. 3 Spec. 



Agreeing" in shape with the mentioned figures; two of the specimens seem to be young- 



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