INSTITUTE OF SCIENCE, PHILADELPHIA. 15 I 



not impossible, however, that they may prove to be the young of Murex 

 Biirnsii Whitfield, the systematic place of which is uncertain, with the proba- 

 bilities in favor of its proving to be a Favartia. 



Genus TYPHIS Montfort. 



This genus, though never very numerous in species, is of a respectable 

 antiquity, some having been described from the Cretaceous period. 



The oldest American species is T. antiqims Gabb, described from the transi- 

 tion beds of the Chico-Tejon series in California, about corresponding to the 

 Ripley sands of Alabama: It is a fully developed Typhis, and the genus must 

 have originated at a still earlier period. In Mid-Eocene we have the T. 

 gracilis of the Claiborne sands, and the Upper Eocene Vicksburg beds afford 

 the T. airvirostraius Conrad. 



In the earlier Miocene we have T. alatus Sby. of the Haitian Miocene, 

 which, according to Guppy, persists into the Pliocene of Trinidad ; and its 

 variety T. obesus Gabb, with a shorter spire and wider varices. There are also 

 T. aciiticosta Conrad of the Miocene of Maryland, and T. linguiferus Dall of 

 the Chipola beds. The Pliocene affords the T.floridanus. The Post-Plio- 

 cene has not offered any species of Typhis as yet; while in the present fauna, 

 unless T. expansus Sowerby, described without habitat, be West Indian, there 

 is no species of typical Typhis to be found. All the foregoing have four 

 varices and the tubes are situated between the varices. There are two recent 

 forms in the region : T. longicornis Dall, which is a Trubatsa, with the tube 

 and varix fused, but the other characters of Typliis ; and T. cancellahts Sower- 

 by, which is like a rude, small, three-varixed Cerostoma with a tubular spine 

 in the shoulder-angle of the varix and no tooth at the aperture. In this case 

 the tube is formed at the same time as the varix, while in Trubaisa the tube is 

 formed first and the varix afterward. The group represented by T. cancellatus 

 may take the name of Pterotyphis, in a subgeneric sense, that being one of 

 three or four names imposed upon it at the same time by the same gentle- 

 man, and based on varietal forms of the same species, according to Tryon. 



Typhis alatus Sowerby, var. obesus Gabb. 

 Typhis alalus Sby., Geol. Journ. vi. p. 48, pi. x. fig. 4, 1850. 

 T. obesus Gabb, Geol. Santo Dotn., p. 203, 1873, 

 T. alatus var., Guppy, Quart. Journ. Geol. Soc, Nov., 1S76, p. 522. 



Miocene of Haiti, Jamaica, and of the Chipola beds, near Bailey's Ferry, 

 Chipola River, W. Florida. Pliocene of Trinidad (Guppy). 



A single specimen was collected by Mr. Burns at Chipola which differs 

 from T. alatus in the manner described by Mr. Gabb. It is the broadest and 

 shortest of our fossil species. 



