414 Zoological Society, 



and the roots of the mangroves. Mr. Gray (vide Proc. Z. S. 1833, 

 p. 112) states he has found the Rissoa similarly suspended. From 

 the swamps of Singapore and banks of rivers in Borneo. 



The animals of Quoyia are amphibious like Conovuli, being found 

 in the shallow water at the roots of the mangroves or adhering to 

 stones not far inland, but exposed to the sun. They are fond of 

 those little bays where the water is shallow and the ripple gentle. 



In Phorus the separation from the foot is by a large space pro- 

 duced into a subcylindrical annulated trunk. The tentacles are 

 tapering and elongate, with the eyes sessile on the outside of their 

 base. The foot is small and divided into two parts, the front rather 

 expanded, the hind part small and tapering, carrying a large oper- 

 culum. Operculum ovate, subannular? Penis elongate fusiform 

 from the right side, rather below the base of the tentacula. These 

 animals are small for the size of the mouth of the shell, and have 

 much the general appearance of the animal of Strombus, like which 

 they appear to walk, but their eyes are sessile. In colour they are 

 dull opake white, the proboscis pinkish and the eyes black. They 

 crawl like a tortoise by lifting and throwing forward the shell with 

 the tentacles stretched out, the proboscis bent down and the oper- 

 culum trailing behind. They are numerous in the Javan and China 

 seas, preferring deep water, and a bottom composed of detritus of 

 dead shells and sand mixed with mud. 



This genus has been generally placed with the Trochi, and some 

 have proposed to remove it to near Calyptrcea ; but Mr. Gray, in his 

 systematic arrangement of the genera of mollusca published in the 

 Synopsis to the British Museum (1840), p. 119, formed for this 

 genus a peculiar family under the name of Phoridce, having observed 

 that the animal, though a Phytophagous mollusk, had the annular 

 operculum of the zoophagous division. 



The animal of Terehellum has an annulated elongate proboscis 

 with a central groove. The eyes are on the end of long cylindrical 

 peduncles, one placed on each side of the base of the trunk and un- 

 equal in length and origin. The body is thick and short ; the foot 

 ovate, broad, rounded in front and tapering behind. Operculum tri- 

 angular, small, and serrated on the outer side with a great part free. 

 This genus is on the confines of the family of Stromhida, where 

 Mr. Gray first proposed to place it (see Synopsis, British Museum, 

 1841, p. 84, and 1842, pp. 52 and 89), for it agrees with the animal 

 of that group in having the eyes placed at the ends of elongated pe- 

 duncles, and in having the operculum triangular and serrated on the 

 outer edge ; but it differs from them in having no tentacula arising 

 from the upper part of the peduncle beneath the eyes, and in having 

 a thicker body and a broader and flatter foot. 



One specimen, from which I made a sketch, was taken in the 

 Javan sea, the other is from the Caramata Passage. 



The animal is exceedingly shy and timid, retracting its body into 

 the shell on the slightest alarm. It will remain stationary for a long 

 time, moving its tentacula about cautiously in every direction, when 

 suddenly it will roll over its shell and continue again perfectly quiet. 



