62 



BuivLKTiN 39 



«34 



Pleurotoma consora, Guppy, 1866, Quart. Jour. Geol. Soc. IvOndon, 

 vol. 22, p. 280. 



Tun^is {Drillia) viilitaris, Gabb, 1873, Trans. Amer. Phil. Soc, vol. 



15, p. 207. Not of Hinds, 1843. 

 Pleurotoma cousors, Guppy, 1876, Quart. Jour. Geol. Soc. London, vol. 



32, p. 527- 



Drillia niilitaris, Gabb, 188 1, Jour. Acad. Nat. Sci. Phila. ,vol. 8, and 

 series, p. 337. 



Pleurotoma alesiilota, Dall, var. magma Bose, 1908, Bol. Inst. Geol de 



Mexico, No. 22, p. 47, pi. 5, figs. 30, 31, 33, 45, 

 Pletirotama sp. aff. PI. alesidota (Dall) var. macilenta Toula, 191 1, 



Jahrb. der K-K Geol. Reichsanstalt Wien.vol. 61, p. 506, pi, 30, fig. 



II. l:^ot alesidota or macilenta Dall, 1889. 

 Drillia cousors Brovvu and Pilsbry, 191 1, Proc. Acad Nat. Sci. Phila., 



vol. 63, p. 345. 



Drillia consors, Cossmann, 1913, Jour, de Conchyliologie, vol. 61, p. 

 20, pi. 2, figs. 8-14. 



Drillia consors, Maury, 1917, Bull, Amer. Pal., vol. 5, p. 216, pi. 8, 

 figs. 15, 16. 



This species is easily distinguished from the venusta, by its 

 more slender form, wide but shallow anal fasciole, sharper sculp- 

 ture and straight, longer, anterior canal. The most common 

 variety, illustrated b}^ figure 10, averages in length about 35 

 mm. The axial ribs are numerous (about 28), straight or 

 slightly oblique and only slightly heavier than the raised spiral 

 cords. In addition the surface is overrun by fine and almost mi- 

 croscopic spirals. Figure 8 of a large variety from Grape Point, 

 has about 9 whorls and measures 60 mm in length. The early 

 spire-whorls have the usual sculpture as seen on typical censors. 

 On about the seventh whorl, the ribe increase suddenly to near- 

 ly twice their normal number. They gradually become obsolete, 

 so that on the last whorl, pratically only the spirals are left. 

 The fine, microscopic spirals seen on typical co7isors are lack- 

 ing. 



The Drillia alesidota and its variety macilenta Dall of the 

 recent West Indian fauna, are closely related to cousors. 



