OF CONCHOLOGY. 13 



foot is almost circulnr, tough and muscular, without any sinus, 

 tubercles or other appendages. The animal appeared to have 

 the power of inflating the cellular tissue between the epiilermis 

 and the sides of the foot, in such a manner as to have the ap- 

 pearance of blisters. These protuberances are persistent in 

 alcohol, though they do not exist in the normal condition. In 

 alcoholic specimens such might readily be taken for lobes or ex- 

 pansions of the foot. The mantle edge is simple, broad and 

 continuous. It is thickened on the right side above the head, 

 and in this thickened portion is the opening of the pulmonary 

 chamber. It is angular, very minute and closed by a small 

 triangular valve or lobe. The head is broad and flattened. 

 There are no tentacles, or rather the tentacles are consolidated 

 and lost in the expanded lobes of the muzzle. The latter is 

 bifid, and the outer extremities are produced into two funnel- 

 shaped expansions, which I will call " ears." The ears are not 

 continuous, but their inner ventral edges overlap one another, 

 while their dorsal edges are separated at their points of inser- 

 tion by a space as wide as the mouth, which is situated just 

 below in the centre of the double funnel. The edges of the ears 

 in the adult are simple, but, according to Dr. Cooper, in their 

 young state they are flattened and pectinated. In the adult 

 their inner surface is marked with moderately conspicuous folds 

 radiating from the mouth. Their exterior surface is smooth. 



The eyes are very minute and black ; they are situated on the 

 sides of the head just behind the ears. In alcoholic specimens, 

 on account of the opacity of the cuticle, they are invisible, but 

 may easily be found by shaving ofl' a thin paring of skin with a 

 sharp knife. 



On the right side between the mantle and the foot is a small 

 papilla, indicating the genital orifice. Just behind the right 

 eye is an almost invisible foramen, exceedingly minute, through 

 which the verge is exserted. 



The mantle and foot exude a peculiar milky slime, with a 

 strong soap-like odor. 



The head is capable of considerable extension and retraction. 



31uscular System. The foot is composed of solid muscular 

 fibre, radiating from a median line. The superior surface, when 

 the viscera are removed, is opalescent. The adductor muscles 

 are horseshoe-shaped and continuous. The anterior right hand 

 limb is broader at its extremity, which is rounded, The edges 

 of the muscular impression are somewhat irregular. The faintly 

 marked sinus passes close to the anterior extremity of the 

 muscle on the right. On the left the mantle is attached to the 

 shell, forming a small oval impression, which is not contuiuous 

 with the scar of the adductor. 



