Zoological Society. 413 



back of the shell than the right. The end of the tentacula and 

 siphon in this species is yellow and the basal part streaked with car- 

 mine. The foot and mantle are semi-transparent flesh-colour, streaked 

 with deep carmine. 



These Marginellce are quicker and more lively in their movements 

 than Cypraa, crawling pretty briskly and moving their tentacles in 

 various directions. 



The head of Eulima is small ; the tentacles are subulate, close to- 

 gether at the base, rather thicker at that part, and slender beyond. 

 The eyes are placed on the back of the head behind the base of the 

 tentacles. The foot is rather expanded, rounded and somewhat pro- 

 duced on each side in front, and rounded in behind. Operculum 

 ovate, subspiral. The animal is entirely opake pearly white. The 

 eyes black and generally concealed under the front of the shell. 

 Tentacles yellow at the tip, orange in the middle, and white at the 

 base. 



Mr. Gray states that he places this genus with the family Pyramid 

 dellidce in his arrangement, and it chiefly diff^ers from Pyramidella in 

 having no plaits on the pillar-lip. It is a slow and excessively timid 

 animal. From eight fathoms water ; Philippines. 



The tentacula of the more elongated species of Melania are subu- 

 late, close together at the base, with the eyes on short peduncles on 

 the outer side of the base. The trunk is oblong, expanded and an- 

 nulated, with a central cylindrical groove. The foot is expanded, 

 rather produced and acute behind, with the operculum on the front 

 of the upper surface. Operculum orbicular and many-whorled. They 

 are generally found partially buried in the ooze formed by decayed 

 vegetable matter where weeds abound, and where the water is verging 

 towards stagnation. 



The animal of Turritella is rather small for the size of the aperture 

 of the shell ; the head is small and oblong ; the tentacula short and 

 subulate, with the eyes on the middle of their outer side. The foot 

 is moderate and slightly notched in front. Operculum orbicular, 

 horny, many-whorled, with an epidermic fimbriated margin. 



This mollusk is very shy and sensitive, retiring quickly within its 

 shell on the slightest alarm. It is slow-moving and inactive. 



The tentacula of Pleurotoma are subulate and close together at 

 the base, and the eyes are near the outer side of the tip, which latter 

 tapers off beyond them. They generally inhabit pretty deep water 

 and crawl tolerably fast. 



Fusus, Lam., has an elongated subcylindrical siphon, with subulate 

 tentacles close together at the base, and becoming more slender be- 

 yond the eyes. Eyes placed rather above the middle of the outer 

 side. Foot moderate. Operculum annular, oblong. 



The Cerithium truncatum has a broad suborbicular and expanded 

 foot, and an elongated subcylindrical annulated trunk. The tenta- 

 cula are short with the eyes at the tip. It is found generally in 

 brackish water in mangrove swamps and the mouths of rivers. Some- 

 times they crawl on the stones and leaves in the neighbourhood, and 

 sometimes they are found suspended by glutinous threads to boughs 



