Costa Rica Miocene — Oi^sson 



113 



Gatun Stage: Coll. 5, Old Ma?i Sam Creek, 

 Codes Creek. 



Genus SOLENOSTEIRA Dall 



SoSenosteira Dalli, Brown and Pilsbry Plate 8, figure 8 



Solenosteira dalli. Brown and Pilsbry, 191 1, Proc. Acad. Nat. Sci, 



Phila., vol, 63, p. 348, pi. 24, fig. 14. 

 Coralliophila gatunensis Toula, 191 1, Jahrb. der K-K Geol. Reichsan- 



stalt, vol. 61, p. 502, pi. 30, fig. 9. 



A common species in the Canal Zone and figured here for 

 comparision with the following species. The whorls are strong- 

 ly shouldered, a feature accentuated by the few, but high, angled 

 ribs. The spirals are heavy, raised cords, over and between 

 which are finer secondary and tertiary threads. 



lycngth 34, diameter 23, last whorl 27, spire 15 mm. 

 Gatun Stage: Gatim, Mi. Hope, C. Z. 



Solenosteira Vaughani Dall, var, medioamerscana, n. var. Plate 8, fig. 7 



cf. Solenosteira VaugJia^ii Dall, 1903, Trans. Wagner Free Inst. Sci., 

 vol. 3, pt. 6, p. 1633, pi. 60, fig. 18. 



Shell solid, with a small pointed nucleus of 2 smooth whorls, 

 and 6 post-nuclear; spire conic, of about >^ the total length of 

 the shell; whorls convex, or bluntly shouldered about the mid- 

 dle ; sculpture of numerous low ribs which are rounded, and 

 heaviest on the shoulder angles; There are 7 to 10 ribs on the 

 last whorl; spirals of raised cords, with finer threads on the in- 

 terspaces; the spire- whorls have about 6 primary spirals, the last 

 whorl with 18, including those of the short canal; canal short 

 with a deep but narrow umbilical pit; aperture oval, a thick in- 

 ner and outer lip, the outer with about 10, long, entering lirse 

 and the inner with three small denticles above. 



Length 42, diameter 24, last whorl 34, spire 17 mm. 

 34 21.5 28 13 mm. 



The Solejiosteira Vaughani is a Chesapeake Miocene species 



