MUSEUM OF COMPARATIVE ZOOLOGY. 389 



umbilicus seems to be constant even in the variety aspina, while in L. Bairdii 

 the sculpture rounds pretty evenly toward the smaller and hardly sculptured 

 umbilical perforation. 



Liotia Bairdii n s. 



Plate XXXIII. Fig. 8. 



Shell of much the same general form as L. Briareus, but having nodnled 

 instead of spinose ridges and a finer and less evident surface sculpture, which 

 follows the incremental lines, and is not wavy, raised, and sharp, as in Briareus. 

 On the last whorl there are six basal, two peripheral, and three superior re- 

 volving ridcres. The suture is channelled, and the middle one of the three 



no ' 



upper spirals is smaller than the two others, which gives a slight tabulation to 

 the spire. It has five whorls and a small smooth nucleus. Like L. Briareus, 

 there is hardly any varix at the aperture of the adult, though this is slightly 

 reflected ; the margin is machicolated by the squarish ends of the spiral ridges, 

 when these are strong. The umbilicus is small, the base in the adult rounds 

 into it, within there is a single rounded spiral ridge, but no spines or nodules. 

 The outer basal spiral is larger than the others, and separated from the others 

 by wider channels. The color is whitish, more or less maculated, or wholly 

 overspread by a dull livid red, much less attractive than the delicate color of 

 the preceding species. The size of the largest specimens is rather less than in 

 Briareus. Operculum horny. Max. alt., 6.0; max. diam., 6.0 mm. 



L. Bairdii var. trullata. Shell having the nodules produced into squarish 

 spines, which are produced parallel to the surface of the whorl and flattened, 

 with fine longitudinal striation outside. These widen toward their distal ends, 

 and recall the appearance of trees which have grown exposed to a steady wind 

 in one direction. They are hardly at all concave on the under side, and are 

 pretty uniform over the base and all the rest of the shell, smaller on the 

 smaller spiral ridges. 



Habitat. Station 2, in 805 fms. ; Sand Key, in 15 fms. ; Sigstee, off Havana, 

 in 127 fms. Also at Stations 2595, 2596, and 2612 of the U. S. Fish Com- 

 mission, in 50-60 fms., twenty miles off the North Carolina coast, and at 

 Stations 2317 and 2318, living, in 45 fms., off Key West. 



Liotia tricarinata Stearns. 



Architectonica tricarinata Stearns, Proc. Bost. Soc. Nat. Hist., for 1872, p. 23, Jan., 

 1872. 



Habitat. West of Florida, in 15 fms. U. S. Fish Commission Stations 

 2598, 2608, 2610, 2615, 2617, and 2619, in 14-22 fms., gravel, off the coast of 

 North Carolina. Caloosahatchie Pliocene beds, near Fort Thompson, on the 

 Caloosahatchie Kiver, South Florida, Dall. 



Some of the fossil specimens of this very pretty little species are nearly 

 twice as large as any which have yet been dredged in the recent state. 



