436 D)'. R. Woodicard — Recent and Fossil Pleurotomarice. 



Mr. W. H. Dall gives the following general description of 

 Pleurotomaria : 



" Shell trochoid in form, internally pearly, the last whorl per- 

 forated or fissured for the escape of eggs, or fecal matters, in the 

 direction of the coil of the whorl. 



" Operculum horny, subspiral or multispiral. Branchiee two, nearly 

 symmetrical, one on each side of the slit in the mantle corresponding 

 to the fissure or perforations of the shell. 



"Animal with papillose edge to the mantle and lateral fringes; 

 without elongated cirri as in the Trochids ; with no frontal veil, or 

 fissuring of the foot. Muzzle simple, without a proboscis, eyes on 

 pedicels exterior to the bases of the simple tentacles. Jaws small, 

 weak." Then follows a description of the odontophore. 



Mr. Dall adds: "A description of the soft parts of PI. Qiwyana 

 and PI. Adansoniana, with figures of the animal taken from life, is 

 in preparation. It is to be regretted that the account will be 

 rendered rather imperfect on account of the poor state in which the 

 soft parts have come to hand. The more delicate portions were 

 entirely destroyed. Those parts of importance in classification, 

 being of a tougher nature, for the most part can be tolerably well 

 made out. SufiScient is already known to show that the group 

 possesses characters of family value, and stands nearest the Trochidce, 

 with features recalling Haliotidce ; and that it has nothing whatever 

 in common with the Pleurotomidce" (op. cit. p. 79). 



Remarks on the other living Pleurotomarice : — 



PI. Qiwyana, Fischer and Bernhardi, 1856, was the first species of 

 living Pleurotomarice discovered. The type specimen (now in Miss 

 De Burgh's cabinet) was figured in the Journal de Conchyliologie, 

 1856, vol. V. p. 165, pi. V. It is the smallest of living Pleurotomarice, 

 being onlj'^ 35 millimetres in diameter, and 45 mm. in height. 



The first specimen was obtained in a lobster-pot or trap sunk in 

 deep water off the island of Marie-Galante, and between that little 

 island and Dominique (H. Crosse, op. cit, 1882, p. 15). It was 

 occupied by a living hermit-crab. 



Two other specimens were dredged alive off Barbadoes by the 

 "Blake Expedition" under A. Agassiz, in 73 and 84 fathoms water 

 (Mus. Comp. Anat. and Zool. Camb. Mass.). 



PI. Adansoniana, Crosse and Fischer (1861), is twice the size of 

 PI. Qiwyana, and extremely like it in its neat and regular ornamenta- 

 tion ; but the position of the slit-band, which is supramedian on the 

 former, is median on the whorls of the latter species ; whereas in 

 PL Beyrichii it is inframedian in position. In both the West Indian 

 species the coils of the shell are rather angular, and the slit-band 

 is more prominent, and distinct. 



(In PL Beyrichii the slit-band nearly coincides with the suture in 

 all but the body-whorl, in which its position is seen to be much 

 below the centre of the whorl. The whorls are more rounded than 

 in the West Indian species, and the outline is therefore more graceful 

 and elegant). 



The specimens have been obtained as follows : — Islet of Fajou, 



