Clark: The San Lorenzo Series of Middle California 175 



Family Buccinidae 

 Genus SEARLESIA Harmer 

 SBARLESIA DALLI, n. sp. 

 Plate 20, figures 5, 9 and 15 

 Type specimen 11215, Coll. Invert. Palae. Univ. Calif., loc. 2754 



Shell medium in size, rather heavy; spire fairly high; number of whorls five 

 or six; apex acute; sutures impressed, the surface of each whorl just below the 

 suture being slightly concave, giving it a collar-like effect. Sides of whorls 

 convex; body whorl rather ventricose, about two-thirds the height of the shell. 

 Whorls covered by numerous, spiral ribs and riblets ; interspaces between ribs 

 somewhat variable, averaging less in width than the tops of the ribs; there is a 

 well-defined riblet in most of the interspaces. On lower whorls of spire there are 

 about nine or ten, and on body whorl from twenty to twenty-five spiral ribs. 

 Surface also sculptured by about sixteen longitudinal, rounded ribs; on whorls 

 of spire these begin a little below the upper suture and extend to the suture in 

 front; longitudinal ribbing on body whorl obsolete except on the immature speci- 

 mens. Aperture semilunate; outer lip thin; inner lip incrusted. Columella 

 subperf orate ; canal short, slightly recurved. 



Occurrence. — University of California localities 14, 217, 1131 and 2754. 



Named in honor of Dr. W. H. Dall of the Smithsonian Institution. 



This species appears to be of the same general type as Serlesia dira 

 (Reeve) 140 = Chrysodomus dims (Reeve). It is rather common in 

 the San Ramon formation but so far no perfect specimens have been 

 obtained. 



Genus CHRYSODOMUS Swains 

 CHRYSODOMUS? PULCHERRIMUS, n. sp. 

 Plate 22, figure 4 

 Type specimen 11222, Coll. Invert. Palae. Univ. Calif., loc. 1131 



Shell rather small; spire acute, with five or six whorls; sutures depressed. 

 Sides of whorls regularly convex ; body whorl strongly and regularly ventricose, 

 nearly two-thirds the height of the shell. Surface sculptured by numerous, rather 

 finely nodose, spiral ribs, the interspaces between which on the body whorl may 

 be a little wider than the ribs, while on whorls of spire they are narrower ; a 

 nodose spiral riblet in each interspace on upper part of body whorl ; these are 

 not in evidence on whorls of spire. On body whorl are about twelve to fourteen, 

 and on whorls of spire four or five of major spiral ribs. The shell has the appear- 

 ance of being sculptured by numerous fine longitudinal ribs ; this, however, is 

 due to the fact that the nodes on the different spiral ribs are in line. Apertura 

 elongate-ovate ; outer lip sharp ; inner lip not incrusted. Canal medium in 

 length, imperforate, slightly recurved. 



Dimensions. — Height, 8+ mm.; height of body whorl, 6+ mm.; maximum 

 width of body whorl, 5 mm. 



Occurrence. — University of California localities 1131 and 2754. 



140 For original description of Scarlcsia dira, see Reeve, L. A., Conchologia 

 Iconiea, vol. 3, Monograph of genus Buceinum, opposite plate 12, figure 92, 184(3. 



