310 University of California Publications in Geology [Vol. 10 



Whorls crossed by about twelve prominent rounded ridges which are 

 highest at shoulder and become nearly obsolete at the upper and the 

 lower part of the whorl. Spiral sculpture on body whorl consists of 

 approximately twenty distinct ribs with very narrow interspaces ; 

 whorls of spire with about eight spiral ribs. Aperture pyriform ; 

 canal broken. Dimensions : Maximum diameter, 28 mm. ; height 

 unknown. 



Occurrence. — In the Santa Margarita, at locality 3029. 



PURPURA NANNA, n. sp. 

 Plate 19, figures la, lb 

 Type specimen, no. 11315, in Univ. Calif. Coll. Invert. Palae., from locality 

 2279, near center of SE % of NE % sec. 15, T. 19 S, E. 15 E, M. D. B. & M., 

 about nine miles northeast of Coalmga. 



Shell muriciform, thick, medium in size ; with three prominent, 

 thick, longitudinal varices on each whorl. Body whorl ornamented 

 with six or seven well-developed spiral cords alternating with cords 

 of less prominence ; in the interspaces between the two series may 

 be seen on well-preserved specimens one or two threadlets ; at the 

 shoulder between each pair of axial varices is a prominent node. 

 Aperture acutely elliptical ; outer lip thick, dentate along inner edge ; 

 inner lip with thin callus ; canal in type closed, curved. Dimensions : 

 Maximum diameter, 34 mm. ; height of type, which has a broken 

 spire, 51 mm. 



This species resembles somewhat closely Purpura foliata Martyn; 

 but has a somewhat more elongated form, stronger nodes between the 

 varices, a development of fine threadlets between the spiral cords, 

 and the varix on the front side of body whorl projects forwards, thus 

 not having the flattened appearance evident on a front view of Pur- 

 pura foliata Martyn. 



Occurrence. — At locality 2279, in the upper part of the Santa 

 Margarita. 



TEGULA THEA, n. sp. 

 Plate 20, figures 6, 7a, 7b 



Type specimen, no. 11317, from locality 2275, near SW corner of NE y± of 

 NE % sec. 33, T. 18 S,.R. 15 E, M. D. B. & M., eleven miles northeast of 

 Coalinga. 



Shell conical ; apex acute ; suture slightly depressed ; whorls about 

 five, with flattened sides and well-marked shoulder. Body whorl 

 ornamented by three broad spiral ridges of which the one near the 



