274 f AMERICAN JOUKNAL 



It is not improbable that a large number of tropical species will 

 eventuallv be referred to it, when their soft parts shall have been 

 examined. Pending such an examination, it is not worth while 

 to so refer any species which have not been dissected, even pro- 

 visionally. I suspect, however, that P. granulans and some 

 allied forms will be found to agree more nearly with Patinella 

 than with Patella, as restricted. 



Patinella, sp. indet. Plate 15, fig. 25. 



Mantle bordered with two rows of fleshy elongated papillx. 

 Foot with a scalloped flounce or frill extending all around except 

 under the head. Muzzle short, broad ; disk fringed with beauti- 

 fully arborescent papilli^ ; indented below. 



Anus prominent, stellate with five rays, richly papillose inside ; 

 renal and infra-anal papillte small, inconspicuous, close to anal. 



A specimen of a very large Patinella, without any shell or 

 number by which the species might be identified, was found in 

 the bottle with known Magellan species. It afi"orded a second 

 opportunity of figuring the dentition of this geinj^s, and w^as 

 noteworthy in the particulars just mentioned. 



Genus NACELLA, Schum. 



Nacella, Schum., Essai d'un Nouv. Syst. 1817, p. 179. Gray, 

 P. Z. S. 1847, p. 165 : in Patellidie. Ibid., Guide Moll. 

 1857, p. 169 ; in Tecturidro. 

 < Nacelhiy Chenu, Man. de Conchyl. i, p. 378. "Woodw., Man. 

 p. 155. Ad., Gen. Rec. Moll, i, p. 467 ; in Patellidje. 

 Cpr., Lect. 1860, p. 70. Second, ed. p. 72. 



Shell with the apex submarginal, anterior ; pellucid, thin or 

 corneous ; animal with the cordon complete before and behind, 

 the laminie persistent but diminishing in size before the head. 

 Sides of the foot provided with scalloped lappets. Teeth, 



3(2— 1-1— 2)3 - Second and third laterals large, subequal. 



Notwithstanding the manner in which Gray has treated this 

 genus, which would lead, by implication, to the belief that he 

 had not only examined the external parts of the animal, but 

 also the dentition, the weight of evidence is too great to be 

 disregarded, and I believe Deshayes to be correct in identifying 

 the type XaceUa m//ti'Ioide$ of Schumacher with P. ci/nibnlaria 

 of Lamarck, Avhich becomes a synonym of nii/tiU)ia, Gmelin. 



Type Nacella mytilina, Gmel. sp. Plate 16, fig. 26. 



Patella nii/tilina, Gmelin, Syst. Nat. 1792, vol. i, part vi, 

 p. 3698, No. 28. (Favart d'Herbigny, Dictionnaire 



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