INSTITUTE OF SCIENCE, PHILADELPHIA. 157 



Strong, prominent, rounded ribs, which are generally sharp-edged and over- 

 hanging in front, rarely continuous at this point with the general surface, 

 usually extending clear across the shell, most prominent at the periphery ; 

 suture very distinct, never appressed ; canal short, narrow, often considerably 

 recurved; aperture ovate, inner lip, smooth and callous, outer lip sharp-edged, 

 following the sculpture, internally with six or eight denticles at resting-stages ; 

 umbilical pit prominent, not deep, bounded by the fasciole, more or less ir- 

 regular and variable ; spire variable in height, usually acute at the tip. Max, 

 Ion. of adult 28.0; diam. 14.0 mm. 



Pliocene marls of the Caloosahatchie and Shell Creek. 



This species is especially marked by its deep and conspicuous suture. In 

 other respects it varies like the rest of the genus, though the overhanging 

 character of the ribs is pretty constant. This is due to the habit, when growth 

 commences after a resting-stage, for the new growth to commence a little in- 

 side the edge of the outer lip of the resting-stage, instead of (as is usual) at 

 the edge of that lip. 



The specimen figured has the canal somewhat worn and imperfect. Better 

 ones were afterward obtained too late for figuring. 



Ooralliophila abbreviata Lamarck. 



Pliocene of the Caloosahatchie beds, Dall. 



A few specimens agreeing fairly well with a fusiform variety of C. abbrevi- 

 ata were collected in the marl. The shell is small, subfusiform, with the whorl 

 much appressed at the suture, giving a conical aspect to the spire, and a small 

 umbilical chink. The canal is rather more slender and constricted off from 

 the base than in any recent specimens I have seen, and a single thread a little 

 more prominent than the other spirals encircles the whorls at the periphery. 



Suborder STREPTODONTA. 

 Superfamily PTENOGLOSSA. 



Family SCALID^. 



Genus SCALA Humphrey. 



Scala (Humphr.) Dall, Rep. Blake Gastr., p. 299, 1889. 



Scala uncinaticosta Orbigny. 



Scalaria uncinaiicosta Orbigny, Moll. Cuba, ii. p. 19, pi. xi. figs. 25-27, 1S42. 



A single specimen was collected from the Caloosahatchie marls. The 



species is known in the living state from Barbados to St. Thomas in rather 



deep water. 



Scala turricula Sowerby. 



Scalaria turricula Shy ., Thes., p. 92, figs. 61, 88. 



Scala turricula Morch, Journ. Acad. Nat. Sci. viii. p. 200, 1S76. 



Pliocene of the Caloosahatchie and Shell Creek, Florida. Living in the 



eastern Antilles, and thence northward to Cape Hatteras in 16-22 fathoms. 



