1921] NATURAL SCIENCES OF PHILADELPHIA. 379 



MELANIIDAE. 



Hemisinus truncatus (Gabb) Plate XXXIV, flgs. 14, 15, IR. 



Ectracheliza truncata Gabb, Trans. Amer. Philos. Soc, xv, 1873. p. 214; Proc. 

 A. N. S. Phila. 1872, p. 271, pi. 9, fig. 2. (Feb. 11. 1873). 



Specimens in good condition show more or less minute, weak 

 spiral striation, such as may be traced in the smoother recent species. 

 Traces of color bands, somewhat wider than in the recent Cuban 

 H. ornatus, can be made out on some examples. As in many of the 

 melanians, the spire is extensively truncated, often leaving little 

 more than the last whorl. The shell is larger than any recent An- 

 tillean Hefnisinus, and further differs by the shorter spire and long 

 last whorl, characters which may possibly give Ectracheliza stand- 

 ing as a "section" of Hemisinus; yet it belongs unquestionably 

 to that genus. The largest example measures, length 36.4, diam. 

 24 mm. The author has elsewhere alluded to the evidence for Ant- 

 illean land areas afforded by the'Oligocene (or Miocene) freshwater 

 shells (Nautilus XXVIII, p. 84). 



Type and 8 others, no. 2878 A. N. S. P. 



ARCHITECTONICIDAE. 



Solariidae of authors. 



ArchitectoDica quadriseriata (Sowb.) 



Solarium quadriseriatum Sowb, Journ. Geol. Soc, Lond., vi, 1849, p. 51, pi. 

 10, figs. 8a, b. c. 



Sowerby's figures represent a half grown example. It reaches a 

 diameter of 37 mm. 



Torinia rotundata Gabb. Plate XXXIV, flgs. 18, 19, 20. 



Torlnia rotundata Gabb, Tr. Am. Philos. Soc, xv, 1873, p. 228. 



There are two spiral cinguh at the periphery, with an intermedi- 

 ate thread, the upper cingulus somewhat wider and prominent. 

 Above it there are four flat cinguh, the upper one narrowest, with 

 fewer granules. Several preceding whorls show five spirals. Un- 

 der the lens delicate spiral striae are seen upon them. On the base 

 there are five cinguli, the outer one narrowest, with a thread in the 

 grooves on each side of it. The inner cingulus is toothed around the 

 umbihcus, within which two cords and one or two threads run on the 

 last whorl. The whole surface is closely ribbed radially, the riblets 

 more prominent on the cinguli than in their intervals. 



Alt. 9.6, diam. 13.5 mm.; 6 whorls. 



The holotype is no. 2816 A. N. S. P. 



