231 



Costa Rico Miocenk — Olsson 



59 



Turris albida Maury, 1917, Bull. Amer. Pal., vol. 5, p. 214, pi. 8, figs. 

 4-8. 



This is a common species in the Gatun beds of Central Amer- 

 ica. The usual form is a large, strongly sculptured and should- 

 er shell, which corresponds best to the variety described by 

 Guppy from Jamaica as barretti. Our largest specimen from 

 Toro Cays, Panama measures as follows: I^ength 86, diameter 

 27, last whorl 56 mm. T. albida, is also a common fossil in the 

 Miocene of Santo Domingo, Jamaica, Trinidad and Venezuela. 

 Its geological range is from the Oligocene to the recent. 



Gatun Stage: Gatun.C. Z. 



Toro Cay, Water Cay, Panama. 



Genus LEUC0SYR5WX Ball 



Leucosyrinx chloris, n. sp. Plate 5, fignre 19 



Shell subfusiform, thin, with an acute spire and a long, 

 straight, anterior canal; nucleus small, globular of about 2, 

 smooth, convex whorls; post-nuclear whorls about 7; the spire- 

 whorls are strongly angled in the middle, leaving a wide, con- 

 cave or sloping zone about the upper suture; the sculpture con- 

 sists of small, more or less confluent tubercles on the periphery 

 of the whorls and number on the last whorl about 14; in addi- 

 tion, the whole surface is strongly sculptured with raised, sub- 

 equal, spiral threads; base strongl}^ contracted to the long, 

 straight, anterior canal; the outer lip is broken; anal sinus, as 

 indicated hy the growth lines, lies in the concave zone, close to 

 the upper suture. 



Length 14.50, diameter 5.00, aperture 7.25 mm. 



This appears to be a true Leucosyrinx, characterized by its 

 thin shell, long, anterior canal and acute spire. It occurs in the 

 Bocas shales with Drillia lithocolletoides, cocosina, Terebra benth- 

 alis var. bocasensis and others, shells which are all closelj^ related 

 to recent deep-water species. 



Gatun Stage: Bocas del Toro. 



