MUSEUM OF COMPARATIVE ZOOLOGY. 357 



torn temperature 56°.0. Station 296, off Barbados, in 84 fms., hard bottom, 

 bottom temperature 61°.5 F. 



The shell named by me Margarita filogyra is without doubt in part based 

 on young specimens of Callogaza Watsoni. But with regard to some of the 

 others I am yet puzzled as to whether to so refer them or not. In any case, 

 the weight of probability is in favor of their being eventually united. There 

 are certain differences in the umbilicus to which I do not, in the absence of 

 soft parts, feel able to give a definite value; while the fact that these specimens 

 have a slightly but distinctly thickened lip adds to the obscurity. At all 

 events, whether wholly identical with C. Watsoni or not (Figures 1, 1 a, Plate 

 XXIII., certainly are), the M. filogyra is in an uncertain state, and for that 

 reason I prefer to omit the name in my list of established species until I obtain 

 more definite material for study. I retain the figures which had been prepared 

 of the supposed young shells. 



An adult specimen affords the following notes. The body is yellowish, the 

 sides streaked with ashy gray, a few flecks of which also appear between the 

 tentacles. The body is longer than in Gaza proper and distinctly pointed 

 behind. The tentacles are short and stout, with a small inner angle or expan- 

 sion opposite the distinct eye peduncle, which bears a large, very black eye. 

 The muzzle is pi-oportionately shorter than in Gaza, subeylindrical, granulose 

 at the end, but not laterally expanded. The gill as in Gaza superba, but 

 broader in proportion to its length. The very large anterior lobe of the epi- 

 podium is followed by seven gradual^ decreasing lateral processes, of which 

 five are under the operculum, and are separated by small rounded lobes of the 

 epipodial margin. The posterior angle of the epipodium is pointed as in Gaza, 

 extending considerably beyond the operculum, but not as far as the foot. The 

 dentition differs considerably from that of Gaza. It most nearly resembles 

 that of Forskalia declivis Forskal, as figured by Troschel (Gebiss d. Schneck., 

 II. pi. xxiv. fig. 14). The rhachidian tooth has a single three-pointed cusp, 

 without the accessory denticles of Forskalia, the laterals have two or three 

 accessory denticles, the uncini, unlike Forskalia, are denticulated all along the 

 inner edges of their blade-like cusps, except toward the margin of the radula, 

 where they gradually become simple. It will be observed that in the soft 

 parts there are features which sufficiently distinguish this group from Gaza, 

 according to ordinary standards. 



Subgenus MICROGAZA Dall. 

 Microgaza Dall, Bull. M. C. Z., IX. p. 50, 1881. (Type, M. rotella Dall.) 



Microgaza rotella Dall. 



Plate XXII. Figs. 5, 5 a. 

 Microgaza rotella Dall, Bull. M. C. Z. IX. p. 51, 1881. 



Habitat. Barbados, in 100 fms. Station 2, in 805 fms. Station 20, off 

 Bahia Honda, Cuba, in 220 fms., bottom temperature G2°.C Station 290, off 



