88 TRANSACTIONS OF THE WAGNER FREE 



Turritella perattenuata, nov. sp. Fig. 13. 



Shell very slender, gradually tapering ; whorls very numerous, doubly 

 carinated, the carinae crenulated or beaded, the upper and lower about 

 equally removed from the upper and basal margins of the whorls respec- 

 tively, the upper carina frequently appearing double through the presence 

 of a contiguous additional line ; shoulder of the whorls prominent, with one 

 or two elevated lines ; the concave space between the carinae with two 

 obsoletely crenulated lines, the upper of which is somewhat the more 

 prominent. Aperture quadrangular. 



Length of a restored specimen nearly five inches ; greatest width, 

 .6 inch. 



Common in the banks of the Caloosahatchie below Fort Thompson. 



This shell can be at once distinguished by its extremely elongated or 

 attenuated outline, surpassing in this character all other forms of the genus 

 with which I am acquainted, either recent or fossil. It bears a (super- 

 ficially) close resemblance to Turritella tornata of Guppy (Q. Journ. Geol. 

 Soc., London, xxii, p. 580), a Miocene fossil of the island of Santo Domingo, 

 but differs in its more slender outline, the greater relative elevation of 

 the shoulder, and in the less prominence of the two intermediate lines 

 between the carinae. These are also much more distinctly beaded in T. 

 tornata. Gabb maintains (" Santo Domingo," Trans. Am. Philos. Soc., xv, 

 p. 240) that Guppy's description applies only to a single variety of the 

 species, and enumerates other characters which are by him held to cover 

 other varieties of the species as well. I fail, however, to see upon what 

 ground this emendation to the original description is made. The speci- 

 mens in Mr. Gabb's collection marked T. tornata certainly do embrace 

 two or more distinct forms of Turritella one of which is indisputably 

 Guppy's species, but why these should be all linked together as a single 

 species I do not exactly comprehend. It is true that they bear a general 

 resemblance toward one another, both in outline and ornamentation, but 

 I fail to detect any gradual passage of the one form into the other a con- 

 dition which might naturally be expected on the hypothesis of specific 

 identity at any rate, not into the form which accords precisely with 

 Guppy's description. 



Turritella apicalis, nov. sp. Fig. 14. 



Shell gracefully tapering, with an acute apex ; whorls numerous, 

 straight-sided, carinated above and below, the carinae about equally 

 removed from the upper and lower sutures respectively, distinctly beaded ; 

 a prominent subsutural line, placed about medially on the shoulders of the 

 whorls ; the flattened space between the carinnc with an obscurely beaded 

 sub-median line, and numerous finer lines, which are almost invisible to 

 the naked eye ; the beads of the carinae oblique, and inclined in opposite 



