MUSEUM OF COMPARATIVE ZOOLOGY. 151 



It may also be noted that the peculiar thick anterior plait in S. Prevostiana 

 and concinna is almost paralleled in the S. Stearnsil of Alaska, thou;^di, if the 

 description given in tlie Manual by Dr. Fischer of the dentition of S. concinna 

 be correct, the two species are very properly subgenerically, or even generi- 

 cally separated. Still, the free interchange of characters in the known species 

 would lead us to suspect a similar state of things with those species whose 

 soft parts are not yet known, and it will not be until all have been examined 

 that we can feel confident that any present arrangement will not have to be 

 modified. 



Aurinia dubia Broderip. 



Volula dubia Brod., Zool. Journ., III. p. 81, pi. iii. fig. 1, 1828. 



Fusus tessellatus Scliubert & Wagner, Suppl. Bd. Mart, und Cliemn. Concliyl. Cab., 



p. 24, pi. ccxix. figs. 3048, 3049, 1829. Kiener, Icon. Kec. Shells, Fusus^ 



p. 39, pi. xxix. fig. 1, copied in Reeve, Conch. Icon., IV. Fusus, pi. xiv. fig. 



53, 1847. (Not of Zekeli and Pictet, Fos. Gosaugeb., 1852.) 

 Valuta dubia Sby., Tlies. Concliyl., pi. Iv. fig. 115, 1847 ; Reeve, Conch. Icon. Valuta, 



pi. xxii. fig. 59, 1849. 

 Valuta (Aurinia) dubia H. & A. Ad., Gen. Rec. Moll., I. p. 166, 1853. 

 Valuta ( Volutifusus) dubia Conrad, Am. Journ. Conch., II. p. 66, 1866. 

 Valuta mutabilis Tuomey & Holmes, Plioc. Foss. S. Car., p. 128, pi. xxvii. figs. 5, 6, 



1856. Not of Conrad, Journ. Acad. Nat. Sci. Phil., VII. p. 135, 1838, and 



Am. Journ. Sci., XLI. p. 346, pi. xi. fig. 7, 1841. 

 Valuta (Aulica) dubia Tryon, Man., IV. p. 90, pi. xxvii. figs. 77, 81, 1882. 

 Volula dubia Dohrn, Jahrb. D. Mai. Ges., VI. pp. 150-156, pi. iv. figs. 1-3, 1879. 



Habitat. Florida Reefs, Pourtales , south and west coast of Florida, Dohrn ; 

 U. S. Fish Commission, at Station 2402, between the mouth of the Mississippi 

 and Cedar Keys, in the Gulf of Mexico, lat. 28° 36' N., Ion. 85° 33' W., in 111 

 fms., gray mud, two living specimens ; Station 2603, thirty-six miles S. ^ W. 

 from Cape Hatteras, N. C, in 124 fms., sand; Station 2604, thirty -nine miles 

 S. by W. ^ W. from Cape Hatteras, in 34 fms., yellow sand, bottom tempera- 

 ture 79° F. (dead fragment) ; and Station 2614, thirty-six miles S. E. ^ S. 

 from Cape Lookout, N. C, in 168 fms., gray sand, bottom temperature 48°. 5 F. 

 (fresh young specimen). 



This is probably the most slender species of the genus, and one of the thin- 

 nest, though the specimens figured by Dohrn seem to have been heavier than 

 any of those I have seen, or than are represented by any of the other figures 

 extant. It is covered all over by fine spiral sculpture, no coarser in front than 

 elsewhere; it has also the peculiarity noted in some species of Cymba, of 

 sometimes being covered all over by a sort of whitish glaze, which obscures the 

 suture, the sculpture, and the coloration. Dohrn's figures look as if the shells 

 had been artificially cleaned, to the advantage of their appearance but the loss 

 of scientific value. This species has normally only two plaits, which, in the 

 adult, are generally obsolete ; one of Dohrn's, however, had the columellar edge 

 grooved, as if possessing two additional minor plaits. 



