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University of California Publications in Geology [Vol. 10 



nold, Calyptraea filosa (Gabb), Dendraster, sp., Macoma, cf. inquinala 

 (Desbayes), Nassa calif orniana (Conrad), Ostrea atwoodi Gabb, 

 PapJria staminca (Carpenter), Thais kettlemansis Arnold, Trophon, 

 sp., Turritella, cf. nova Nomland. 



MUREX (OCINEBRA) CONCINNA, n. sp. 

 Plate 12, figures 6, 6a 

 Type specimen no. 11093, Univ. Calif. Coll. Invert. Palae. 



Shell small, subfusiform, with rather low spire. Whorls four or 

 more, increasing rapidly in size. Body-whorl with distinct angles at 

 shoulder and base, giving the sides a flattened appearance. Each 

 whorl with about nine wide, prominent, axial ribs ; on body-whorl these 

 extend from suture down to about middle of canal. The spiral orna- 

 mentation on the body-whorl consists of about eight and on the spire 

 two, high, rounded cords which become fainter on canal ; between these, 

 especially on upper part, are fine thread-like intercalaries ; where the 

 spirals intersect the axial ribs a decidedly nodose appearance is pro- 

 duced. Aperture oblong-elliptical ; outer lip thickened, terminating 

 in a long, narrow, recurved canal ; inner lip slightly incrusted ; colu- 

 mella faintly marked by spiral sculpture. Dimensions : height, 25 mm. ; 

 maximum diameter, about 13 mm. 



Occurrence. — At localities 2643, 2985, middle Etchegoin. 



MUREX (OCINEBRA) TETHYS, n. sp. 

 Plate 12, figures 2, 2a, 2b 

 Type specimen no. 11099, Univ. Calif. Coll. Invert. Palae. 



Shell small, heavy ; whorls four or five ; suture distinct, slightly 

 channeled ; apex acute ; body-whorl large and ventricose. Whorls 

 sculptured by prominent, coarse spiral cords and low, often almost 

 invisible, intercalaries ; the body-whorl has about seven and the spire 

 two of the major cords ; these are crossed by eight high, angular, longi- 

 tudinal ribs which disappear on lower part of body- whorl; where these 

 cross the spirals the shell becomes slightly nodose, this being especially 

 evident on upper part of whorls, where a rather sharp shoulder is 

 produced. Aperture wide, elliptical, with thick outer lip ; inner lip 

 apparently smooth, incrusted ; canal short, slightly curved. Dimen- 

 sions of type : height, 21 mm. ; diameter, 15 mm. 



Apparently this form most closely resembles Ocinebra lurida, var. 

 ccrritensis Arnold, from which it may be distinguished by its higher 



