240 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 2 



Gyclostrema bartschi Strong & Hertlein, new species 

 Plate 21, Figs. 12, 13, 16 



Shell minute, grayish white, depressed turbinate; nuclear whorls 2, 

 smooth, rounded; postnuclear whorls nearly 2, angulated, sculptured 

 with a compressed spiral keel on the strongly angulated periphery and 

 equally strong, slightly curved axial riblets continuous over both spire 

 and base, 24 appearing on the last whorl ; suture strongly appressed 

 with a ridged fold just below it ; in addition to the angle at the periphery 

 the upper surface of the whorls is divided into 3 nearly equal areas by 

 2 angles, the space between the sutural fold and the first angle being 

 concave, while the spaces between the first and second angles and the 

 second angle and the peripheral keel are slightly convex; the axial rib- 

 lets between the subsutural fold and the first angle are nearly vertical 

 and much narrower than on the balance of the shell, while those on 

 the space between the second angle and the peripheral keel become 

 strongly retractive ; base slightly convex between the peripheral keel and 

 the sharply angulated edge to the funnel-shaped umbilicus, into which 

 the axial riblets enter deeply, crossing another angle on the middle of 

 the umbilical wall; aperture nearly circular, the posterior angle falling 

 a little above the peripheral keel, outer lip fairly thick; inner lip curved 

 with a thick callus over the body of the shell. The type measures: 

 greater diameter, 1.0 mm; height, 0.5 mm. 



Holotype: No. 715 (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. Twenty-six additional specimens 

 were dredged at the same locality. 



This species is probably nearer to Cyclostrema miranda Bartsch,^^ 

 described from San Diego, California, than to any other west coast 

 species. It is only about half the size of that species, lacks the spiral cords 

 on the angles of the whorls, and has relatively stronger axial riblets. 



This species is named for Dr. Paul Bartsch, Curator, Division of 

 Mollusks, United States National Museum at Washington, D. C. 



Circulus bakeri Strong & Hertlein, new species 

 Plate 21, Figs. 14, 15; Plate 22, Fig. 1 



Shell minute, depressed, semitransparent ; nuclear whorls 2, well 

 rounded, smooth; postnuclear whorls 2, upper surface of whorls 



66 Cyclostrema miranda Bartsch, Proc. U. S. Nat. Mus., vol. 39, January 9, 

 1911, p. 230, pi. 39, figs. 1, 2, 3. "San Pedro, California." 



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