22 Bulletin 29 186 



Pilsbry, is also sculptured over the anterior half of the body 

 whorl, but the spirals are closer and the spire appears shorter 

 and the body broader than in our shell. 



Locality. — Bluff 3, Cercado de Mao. (Abundant). 



ORDER CTENOBRANCHIATA 



(A.) SUPER-FAMILY TOXOGLOSSA 



Genus Terebra Adanson 



Terebra sulcifera Sowerby 

 Plate 3, Figure 12 



Terebra sulcifera Sowerby, Quart. Jour. Geol. Soc. London, vol. 6, p. 



47. 1849. 

 Terebra robusta Gabb (in part), Trans. Amer. Phil. Soc, vol. 15, p. 



224, 1873. Not T, robusta Hinds, Proc. Zool. Soc, p. 149, 1843. 

 Terebra sulcifera Guppy (in part), Quart. Jour. Geol. Soc, vol. 32, p. 



525, pi. 29, fig. 8. 1876. 



Heneken collected three Terebras in Santo Domingo, which 

 Sowerby named sulcifera, incequalis and bipartita, from their 

 striking characteristic sculpture. 



When Guppy, in 1876, examined the types he found he 

 could establish no constant differences between them aud placed 

 the last two species in the synonymy of the first. The extreme 

 forms are, however, very different in aspect. 



T. sulcifera has the early whorls deeply sculptured, but with 

 age the sculpture is lost and the whorls increase rapidly in diam- 

 eter. Both these characteristics are more remarkably developed 

 in the related species, T. Gabbi Dall. 



The ornamentation of the earlier whorls of T. sulcifera con- 

 sists of two thickened, sub-sutural bands, the second (anterior) 

 being about half the width of the first, and both bands being 

 crossed obliquely by very fine riblets. The two bands occupy 

 about two-thirds of the whorl. The remaining third appears 

 sunken and is crossed by very fine vertical riblets. After ten or 

 more volutions this sculpture becomes progressively weaker, the 



