NO. 12 STRONG AND HERTLEIN : MARINE MOLLUSKS 197 



whorl obscurely angulated ; base short, well rounded, marked by faint 

 continuations of the axial ribs; aperture subquadrate, outer lip broken 

 in the type; columella strong, almost straight. The type measures: 

 length, 5.0 mm; diameter, 1.4 mm. 



Holotype: No. 750 (Calif. Acad. Sci. Paleo. Type Coll.), from 

 Loc. 27,229 (C.A.S.), dredged in from 3 to 9 fms. in Bahia Honda, 

 Panama. L. G. Hertlein collector. Thirty-five additional specimens were 

 dredged at the same locality. 



In the key given by Dall & Bartsch-''' to the west coast species in 

 the subgenus Strioturbonilla, this species would fall between aresta from 

 southern California and pazana from the Gulf of California. It differs 

 from the first in the smaller number of axial ribs and narrowly tabu- 

 lated whorls and from the second in the much broader outline. 



This species is named for Mr. Thomas Cowles, formerly librarian 

 of the California Academy of Sciences, who assisted the writers many 

 times with the library research necessary for the preparation of this 

 paper. 



Turbonilla (Strioturbonilla) mcguirei Strong & Hertlein, 



new species 

 Plate 19, Fig. 1 



Shell elongate-conic, white; nuclear whorls 2^^, forming an ele- 

 vated helicoid spire, the axis being at right angles to that of the first 

 postnuclear whorl, in which it is slightly immersed, with the apex pro- 

 jecting beyond the outline of the following whorls; postnuclear whorls 

 11, moderately rounded, sutures impressed; axial sculpture of slender, 

 moderately protractive, slightly undulated ribs, of which 16 appear on 

 the early whorls, gradually increasing to 20 on the body whorl; inter- 

 costal spaces about twice as wide as the ribs, extending from suture to 

 suture but terminating at the periphery; spiral sculpture of fine, micro- 

 scopic striations over the entire surface; periphery of the last whorl 

 obscurely angulated; base short, well rounded, aperture subquadrate, 

 outer lip thin, showing the external sculpture within ; columella slender, 

 nearly straight. The type measures: length, 4.7 mm; diameter, 1.1 mm. 



Holotype: No. 756 (Calif. Acad. Sci. Paleo. Type Coll.), from 

 Loc. 27,228 (C.A.S.), dredged in from 3 to 9 fms. ofif Taboga Island, 

 Panama. L. G. Hertlein collector. A second but much younger speci- 

 men was dredged at the same locality. 



27 Dall, W. H., and Bartsch, P., U. S. Nat. Mus., Bull. 68, 1909, pp. 40, 41. 



