255 Costa Rico Miocene — Olsson 83 



upper is much larger; a third is probably developed on the an- 

 terior border of the canal; a well marked ridge about the base 

 and a strong siphonal fasciole. 



Height 36, diameter 23, last whorl 29, aperture 24 mm. 

 This shell was figured by Dr. Maury in her Dominican fos- 

 sils as C. Barretti of Guppy, but it differs from that species in 

 much shorter spire, more globose shell, larger aperture and by 

 its columellar plicae. In the species closely related to the reti- 

 culata, such as Barretti, Cossnianni and others, the columellar 

 plicae are heavy and the posterior one is usually more or less 

 bifid. In this species, the posterior plication is large, wide and 

 thin, especially in the interior of the shell. 



The Costa Rican collection is limited to a single, imperfect 

 specimen, so Vv^e have used as the t5'pe of this species, the origi- 

 nal figured specimen of Dr. Maury from the Miocene of Santo 

 Domingo. 



Gatu7i Stage: Water Cay. 



CanceiSaria epistomifera Guppy 



Cancellaria Moorei Gabb. 1872, Trans. Amer. Phil. Soc, vol. 15, p. 

 236. Not C. Moorei Guppy, 1866. 



Cancellaria epistomifera Gupp}^ 1876, Quart. Journ. Geol. Soc. Lon- 

 don, vol. 32, p. 520, pi. 28, fig. 9. 



Cancellaria epistomifera Cossmann, 1913, Journ. de Conchyliologie, 

 vol. 6r, p. 53, pi. 4, figs. 5, 6. 



Cancellaria epistomifera Maury, 1917, Bull. Amer. Pal., vol. 5, p. 227, 

 pi. 10, figs. 3, 4, 5. 



For figures of this species, the reader is referred to Dr. 

 Maury's Dominican Fossils. We have collected a few, small 

 and imperfect specimens at Gatun in the Canal Zone. Small 

 shells are easily confused with the common C. darieiia, but in gen- 

 eral the spire is shorter, and the spiral sculpture is heavier and 

 more regular. At maturity, the outer lip develops below a 

 peculiar and characteristic sulcus or pout, which is not seen on 

 any of the associated species of Cancellaria. 



Gahm Stage: Gatun, C. Z. 



