60 BULLETIN 90, UNITED STATES NATIONAL MUSEUM. 



genus Mitra in the Lamarckian sense. These were 1, M. tessellata 

 Martyn; 2, M. fasciata Martyn {=M. castra Lamarck) ; 3, M. syhmvu- 

 Jata Martyn ; 4, M. nexilis Martyn (belonging to the group of filaris 

 Linnaeus) ; and 5, M. versicolor Martyn (probably afterwards de- 

 scribed as M. nebulosa Swainson). 



It is obvious that the type of the genus and of the typical sec- 

 tion must be one of these species, and not the M. episcopalis which 

 was Lamarck's monotype 15 years later. Numbers 1 and 3 belong 

 the subgenus Scahricola Swainson; No. 2 to the section Swainsonia 

 H. and A. Adams ; No. 4 to the subgenus Cancilla Swainson ; while 

 No. 5 is referred by Tryon to the typical section as sometimes under- 

 stood and to which it is nearest. However, the possession of marked 

 punctate spiral grooving induced Swainson to make a section for it 

 which he called N ehvlaria. This name must give way to Mitra in the 

 strict sense, while for the smooth red-spotted Mitras, hitherto 

 wrongly regarded as typical, the new sectional name Papdlaria may 

 be used. 



The silex bed fossils of this genus belong to the subordinate groups 

 Cancilla Swainson and Fusimitra Conrad, for the most part. 



MITRA SILICATA Dall. 



Plate 14, fig. 2. 



Mitra {mis^issippiensis Conrad, var?) silicata Dall. Trans. Wagner, Inst., 

 vol 3. pt. 1, p. 93, pi. 4, fig. 11. 1890. 



Tampa silex beds between Ballast Point and the town, collected 

 by Mr. Shepard. U. S. Nat Mus. No. 165066. 



This species was included in Conrad's genus Fusimitra (type 31. 

 cellulifera Conrad) since abandoned. 



MITRA SYRA, new species. 



Plate 12, fig. 17. 



Shell small, slender, acute, with about 9 whorls separated by a 

 distinct but not deep suture; nucleus smooth subglobular, the suc- 

 ceeding 3 whorls smooth, or very faintly axially striated, the sculp- 

 tured whorls succeeding abruptly; axial sculpture of (on the pemdti- 

 mate whorl IT) narrow, slightly protractive, rounded ribs extend- 

 ing completely over the whorls to the base on the last whorl, with an 

 inconspicuous contriction near the suture, but otherwise smooth and 

 even, separated by much wider interspaces; spiral sculpture of (be- 

 tween the sutures about 7) flattened close-set cords, which do not 

 override the ribs, and continue to the canal on the last whorl, where 

 they are succeeded by four or five larger and more distant rounded 

 spirals; aperture narrow, sublimate; outer lip simple, hardly thick- 



