Dr. Philippi on the Animal of Pleurotoma Bertrandi. 299 



sata, Brocchi,) and A. fusca {Tellina fusca, Poll,) as two di- 

 stinct species (p. 25^.), but I must persist in my view, that 

 they are identical. I liave at this moment twelve perfect in- 

 dividuals before me ; in which I find every transition, from a 

 perfectly smooth shell, only obliquely grooved at the apices, 

 to one which is covered as far as the margin with great regu- 

 lar grooves. Moreover, the shell is sometimes flat, sometimes 

 strongly vaulted. 



Fig. 6. Astarte incrassata, de la Jonk. One and a half times magnified. 

 The upper mantle lobe is thrown back in some degree, in order to 

 show the form of the foot and the two branchias. 



8. On the Animal of Pleurotoma Bertrandi, Payr. Plate IV. 



%7. 



I have also now seen the living animals of two species of 

 Pleurotoma ; PL Bertrandi was very frequent. That which 

 greatly distinguishes the animals from Fusus is, that they are 

 quite without operculum. The/bo^ when stretched out is some- 

 what longer than the last whorl of the shell, rather narrow, 

 truncated anteriorly, and slightly emarginate, with an oblique 

 groove ; narrowed gradually posteriorly, and at last emargi- 

 nate. The branchial tube projects tolerably far out of the 

 canal. The 7iead is small ; the tentacula are short, filiform and 

 obtuse, thickened half-way up, where they carry the eyes exter- 

 nally ; they do not unite in an acute angle, as is the case in 

 Fusus, Murex, Mitra, but the head forms a slightly rounded 

 projection, just such a one as is seen in the species of Trito^ 

 nium. The colour is transparent, marbled with yellowish-white, 

 sometimes with reddish-white opake points upon the siphon. 

 The other species, either PI. gracile^ or a new nearly allied 

 species, is distinguished, with regard to the animal, from the 

 present species solely by the foot being posteriorly acute, and 

 the siphon being decidedly spotted with red. 



Fig. 7. Pleurotoma Bertrandi, Payr. Magnified four times. 



9. On the Eggs of Vermetus gigas, Bivona. Plate IV. fig. 8. 

 During October and November I found Vei'metus gig as 



almost always with eggs in different stages of development. 



They are inclosed in oval, flatly compressed cases, which have 



* This is Murex attenuatus, Mont. Test. Brit. — J. E. G. 



