INSTITUTE OF SCIENCE, PHILADELPHIA. 393 



Alt. of adult shell 44; max. diam. of base 40; min. diam. 35 mm.; alt. of the 

 last whorl 27 mm. 



The early portion of this splendid shell recalls in its sculpture the variety 

 basicum, with which it almost exactly agrees, but the base, even at that age, is 

 destitute of the six strong subequal spirals which characterize that form, and 

 the adult shell is many times larger than any recorded specimen of either the 

 typical philanthropus or any of its varieties. Yet the similarity of the early 

 whorls is so striking that I cannot feel confident that the present form is dis- 

 tinct. It may be that most of the specimens of philanthroptis hitherto col- 

 lected were shallow-water shells, and that the species in deeper water, as in 

 the case of several recent species, attained a much larger size than their aver- 

 age would indicate. The specimens from which this description was drawn 

 up were lent to the writer by permission of the Academy, and bear no label 

 of exact locality, or name of collector. They are merely indicated as belong- 

 ing to the " Atlantic Miocene " of the United States. The matrix is quite 

 - similar to that of specimens from Petersburg, Va., and they may have been 

 collected there. The only species of our Eastern fauna at all comparable with 

 this fine shell is the C. Sayanum Dall, which is profoundly umbilicated and 

 relatively more depressed. 



Oalliostoma Mitchelli Conrad. 



Trochus Mitchelli Conr., Journ. Acad. Nat. Sci. Phila. vii. p. 137, 1834. 

 Zizyphinus Mitchelli Conr., Proc. Acad. Nat. Sci. Phila. 1862, p. 569, 1863. 



Chesapeake Miocene of Yorktown, Virginia, and Duplin County, North 

 Carolina. 



This fine species is closely related to C. Rtiffiiiii Conrad, but differs by its 

 strong spirals, which are sharply annulate rather than beaded, the periphery 

 being marked by a pair of especially strong ones, the anterior of which be- 

 comes buried in the suture. Although described more than half a century 

 ago, I believe this handsome shell has never been figured. 



Oalliostoma RufHnii H. C. Lea. 



Trochus Ruffinii Lea, Trans. Am. Phil. Soc, 2d Ser. ix. p. 40 (reprint), pi. 37, fig. 86, 



1845. 

 Trochus armillus Lea, op. cit. p. 38, pi. 37, fig. 81, 1845. 

 Trochus torqiiatus Lea, op. cit. p 40, pi. 37, fig. 84, fide O. Meyer, Proc. Am. Phil. Soc. 



XXV. p. 137, 1888. 

 Zizyphinus Ruffinii Conr., Proc. Acad. Nat Sci. 1862, p. 569. 



Chesapeake Miocene of Petersburg, Va., Lea; of Yorktown, G. D. 

 Harris ; Newer Miocene of Cape Fear River, N. C, at Mrs. Purdy's marl-bed, 

 Johnson ; Pliocene of the Waccamaw beds, Waccamaw River, S. Carolina 

 (van), Johnson. 



Several of the Trochids described by H. C. Lea in the paper referred to 

 are unrecognizable tips of larger species, or specimens so young as to be 



