PHVLOGENY OF FUSUS AND ITS ALLIES. 21 



With the typical form occurs a variety which approaches much more 

 closely to F. ttirriculus thau does the species. In fact, the two might 

 be considered identical if found in the same waters. This variety has 

 the typical fusoid protoconch, with narrow riblets on the last two- 

 third whorl. It is slightly more condensed than the Chinese species, 

 not so much through greater embracing of the whorls, but through 

 a greater vertical compression of the whorls, which makes them appear 

 more swollen at the middle. The spirals have the same sharp char- 

 acter where they cross the ribs, but they remain simple somewhat 

 longer, intercalated spirals appearing only in the last whorl, and then 

 not becoming very prominent. The ribs are much less prominent 

 than in the species proper, and they are always more than their width 

 apart, becoming still further separated in the last whorl. 



This variety compares best with immature F. titrriciihis, in which 

 the whorls and ribs have not yet become swollen. 



Localities: Off Key West, U. S. Fish Comm. station 2316, 50 fnis. 

 on coral, temp. 74 degr. 2 spec. (U. S. Nat. Mus. 93647) ; between 

 Tampa and Dry Tortugas, U. S. Fish Comm. Sta. 2411, 27 fms. 

 (U. S. Nat. Mus. 93649) ; off Key west U. S. Fish Comm. Sta. 2317, 

 45 fms. (U. S. Nat. Mus. 835 11) ; off Key West, Sta. 2318, 45 fms. 

 on coral, temp. 75 degrees (U. S. Nat. Mus. 93648). 



Variety : Between Miss. Delta, and Cedar Keys, Sta. 2402, in mud,. 

 Ill fms. 2 specimens (U. S. Nat. Mus. 93650) ; Gulf stream, Stimpson 

 dredge (M. C. Z. 962), i spec. 



FUSUS TURRICULUS Kiener. 



(Plate II, fig. i; Plate XVII, fig. i.) 



1842. Fusus turricula Kiener, Iconographie, p. 6, pi. V, fig. i. 

 1847. Fusus tunicula Kiener, Reeve, Iconica, pi. 6, fig. 23. 



The protoconch of this species represents the typical Fiistcs 

 protoconch. The whole protoconch comprises about one and one half 

 volutions, of which the first is smooth, and the other half furnished 

 with faint crowded, vertical riblets, which 1)ecome stronger towards the 

 end. A strong, smooth varix marks the end of the protoconch. 



The conch begins abruptly, with rounded whorls, rounded ribs, 

 at first somewhat fainter than the terminal varix of the protoconch, and 

 rounded revolving spirals, which produce a strong sculpturing on the 

 ribs. The spirals become stronger, but remain simple for the first two 

 volutions of the conch. Then intercalations begin, at first on the 

 lower part of the whorl, and then farther up. The intercalations be- 

 come compound by the sixth volution of the conch, the stria; near the 

 center at the same time becoming sharper on the ribs, and tlie latter 

 less strongly outlined. In some specimens an incipient flattening 

 appears on the shoulder and with this usually appears a slight peripheral 



