INSTITUTE OF SCIENCE, PHILADELPHIA. I I J 



young the whorl is sparsely spirally striated and somewhat constricted at its 

 base; the adult has the periphery nearly smooth and the base of the whorl 

 more rounded ; the canal appears to be striated, very straight, rather stout, 

 slightly callous, but not grooved ; I find no trace of an infra-sutural ridge or 

 any internal lirse. The adult appears to reach a length of 85 and a diameter 

 of over 50 mm. 



The adult specimen of this remarkable species is too imperfect to figure, 

 though affording information for a diagnosis. I have figured a tip which 

 shows the curious dish-like keel and swollen nucleus of the young. A frag- 

 ment, including most of the canal, found with the adult, is referred to this 

 species with some doubt. It is evidently a rare form, but offers very clear- 

 cut characters to distinguish it from the other species. 



Fulgur maximum Conrad. 

 Busycon niaxi7>ius Conrad, Foss. of Tert. Form. U. S., cover of No. 2, p!. 48, fig. i, May, 



1840. 

 Busycon iritonis Conrad, Proc. Acad. Nat. Sci. Phila. 1862, pp. 561, 5S3 ; Am. Journ. 



Conch, iii. p. 265, pi. 20, fig. 2, 1867. 

 Fulgur maximus Gill, Am. Journ. Conch, iii. p. 146, 1S67. 

 Busycon maximutn Conrad, Am. Journ. Conch, iii. p. 184. 

 '^Fulgur maximus Heilprin, Trans. Wagner Inst. i. p. 72. 

 ? Busycon filosum Conrad, Proc. Acad. Nat. Sci. Phila. 1862, p. 286 ; Am. Journ. Conch. 



iii. p. 266, pi. 21, fig. 7, 1867 (cf. Heilprin, Trans. Wagner Inst. i. p. 72). 

 Fulgur rapum Heilprin, op. cit. p. 71, 1S87. 



Miocene of Florida, in the upper bed at Alum Bluff; of Duplin Co., North 

 Carolina; also at Wilmington, N. C. ; Pliocene of South Carolina? at Dar- 

 lington, where the exact horizon is doubtful and may be Miocene ; Pliocene 

 of the Caloosahatchie beds on the Caloosahatchie River, S. W. Florida, Will- 

 cox, Heilprin and Dall. 



This is an interesting and variable form which may be divided into three 

 varieties, after premising that, as is the case throughout the genus, the females 

 have a wide patulous canal, while the canal in male specimens is much 

 narrower and more cylindrical. 



Var. maximiun (Conrad). Spire short, sloping, with the suture at the 

 shoulder ; no keel or tubercles. 



Var. rapiini (Heilprin). Spire scalar, with the shoulder rounded, nodulous 

 or with distant spines, but no continuous keel. F. tritonis is the extreme of 

 this variety, with a little more sloping shoulder. 



Var. tudiadatiLin Dall. Spire very low, base constricted, last whorl greatly 

 inflated ; shoulder rounded, without keel or tubercles in the adult, excavated 

 somewhat in front of the suture, which is bordered by a tuberculate or wavy 

 elevated band formed by the thickened margin of the whorl being laid over 

 the tuberculated shoulder of the young shell ; canal slender, rather long, the 



