60 Mighels^ and Adams^ Descriptions of 



TURRITELLA COSTULATA. 



Plate IV. Fig. 20. 



T. testa albida ; transverse subtilissirne striatci ; anfractibus decern ; superiori- 

 bus sub-plicatis ; duobus ultimis sub-Iaevibus, ultimo sub-carinato; apertur^ sub- 

 ovata, anterius producta. 



Shell whitish, translucent ; whorls nine or ten, nearly flat, 

 or very slightly convex ; suture well impressed ; last two 

 whorls nearly smooth ; the others longitudinally plicate, with 

 microscopic transverse striae ; last whorl sub-carinate ; aper- 

 ture rather less than one-fourth the length of the shell, snb- 

 ovate, produced anteriorly. 



Length ,7 inch ; breadth .23 inch ; divergence, 22°. 



Habitat. Casco Bay ; taken from the stomach of a had- 

 dock in the summer of 1841. 



Remarks. Although only a single specimen has been ob- 

 tained, its characteristics are so obvious that we have not 

 hesitated to describe it. It has no analogue on our coast, to 

 our knowledge ; it, however, resembles a very much enlarged 

 T. interrupta, Totten. It is in the cabinet of J. W. Mighels. 



TURRITELLA RETICULATA. 



Plate IV. Fig. 19. 



T. testcl turrito-subulata; anfractibus duodecim, convexis, longitudinaliter pli- 

 catis, transversim striatis; sutura valde impressa ; apertura sub-orbiculari. 



Shell turreted, very slender, of a dingy white or ash color ; 

 whorls eleven to twelve, convex, distinctly, though somewhat 

 irregularly plicate longitudinally, with from three to five del- 

 icate, impressed, revolving striae on the five lower whorls ; 

 from and above the fifth whorl the transverse striae gradually 

 diminish in number, until they wholly disappear on the upper 

 two or three whorls. The whole surface of the shell has a 

 reticulated appearance. Suture well impressed ; aperture sub- 

 orbicular ; labrum thin ; operculum horny. 



Length ,7 inch ; breadth ,2 inch ; divergence 20^. 



Cabinets of Bost. Soc. Nat. Hist., Dr. Gould, J. W. Mighels, 

 and C. B. Adams. 



