THK NAUTILUS. lOl 



Cuba, Moluscos, p. 282, pi. 25, f. 23-25 (1845); and in the French 

 edition, p. 217, pi. 25, figs. 23-25, 1853. 



Pholas semicostata H. C. Lea, Proc. Bost. Soc. Nat. Hist. I, 204, 

 1844; Boston, Jour. Nat. Hist. V, p. 285, pi. 24, f. 1, 1845. 



Pholas teredinifvrniis Sowb., Proc. Zool. Soc. 1849, p. 161. 



Pholas Beauiana Recluz, Jour. Conch. IV, p. 49, pi. 2, f. 1-3, 

 1853. ' ' 



Pholas corticaria Sowerby, Tiies. Conch. 11 _ 495, pi. 108, f. 94— 

 96, 1855. 



Martrsin striata Tryon, Mon. Plioladacea, p. 92, 1862. 



Mnrtesla corticaria Tryon, Mon. Pholadacea, p. 92', 1862. 



Shell narrowly wedge-shaped, thin, 'anterior truncated, cordate, 

 with sinuous elevated crenulated ridges, showing slight radial sculp- 

 ture anteriorly ; radial sulcus slight ; the posterior portion marked 

 only by somewhat irregular concentric undulations or growth lines; 

 callum smooth, and angulate at the line of attachment ; the protoplax 

 normally three-lobed, those of the sides sometimes wanting in the 

 smaller specimens, giving tiie protoplax a " halberd-shaped " appear- 

 ance as s!iown in the figure of P. corticaria Sowb. Length, 8-23 mm. 



Distribution, South Carolina, Florida and the West Indies, 

 Europe, Japan (Dunker), Philippines (Cuming). It was described 

 by Linnaeus from southern Europe, while to the West Indian shell 

 he gave the name of P. piisilla. The slight radial sulcus and angular 

 margin of the " callum " of P. semicostata H. C. Lea, shows that it 

 is undoubtedly a synonym of this species. P. terediniformis and P. 

 falcata, as stated by Tryon, are only the young of this species. P. 

 Hornbeckii Orb., also comes under this category. The type of P. 

 corticaria was found in a jtiece of cast-np mahogany. 



Through the kindness of Mr. J. J. White, of Rockledge, Florida, 

 I received an interesting series varying in size from 8-21 mm. lono'. 

 They were collected at Oceanus, Florida. These specimens were 

 also found in drift-wood, a feature which undoubtedly accounts for 

 the wide distribution of this species. 



Martksia cuNEiFORMis.(S.ay). Fig. 2. . . . ,,, 



Pholas cuneiformis Say, Jour. Acad. Nat, vSci. II, p. 322, 1822, 

 Martesia cuneiformis Tryon, Mon. Plioladacea, p. 91, 1862. 

 Shell broadly Wedge-Shaped, anteriorly truncate, cordate ; with 



bro;id siniin-;e crenulated ridges, tlie anterior creiuilations forming 



