230 Lamellar ia tenia culdta. 



there is a minute process, or appendage. The head is truncate 

 with two white awl-shaped tentacula, which are contractile 

 and originate in the anterior angles, having the eyes, which 

 are black and very distinct, at their external bases. The mouth 

 is terminal, furnished within the fleshy lip with small cartilagi- 

 nous jaws, and a long, narrow, linear, or riband-shaped, tongue, 

 roughened with spinules arranged in regular series. Above 

 the head, and under the cloak, there is a large slit which leads 

 to the branchial cavity, and the water of respiration is con- 

 ducted to this wide orifice by a short canal formed by a fold 

 of the cloak ; and it is this fold which produces the frontal 

 sinuation, for there is really no interruption in the margin of 

 the cloak. Within the cavity there was retroflected the male 

 organ of generation, which seems very large in proportion to 

 the animal : it is somewhat compressed, obtuse, with a long 

 point directed backwards. Foot oblong, truncate in front, 

 where it is opaque milk-white, the rest of it beingwatery white. 

 The space between it and the cloak is tinted with black. 



The shell is concealed and embedded in the cloak, occupying 

 a dorsal and central position. It is 3 lines broad and about 

 5 long, ear-shaped, convex, milk-white, even and apparently 

 smooth ; but, when looked at through the magnifier, it is seen 

 to be wrinkled by the lines of growth; spire depressed, small, 

 consisting of a single whorl ; aperture very patulous, oblong, 

 the inferior margin somewhat truncate, the pillar lip flattened, 

 and continued in a spiral form within the shell. 



The creature creeps very slowly, and, when in progression, 

 raises itself orl the foot, while, at the same time, the tentacula 

 are extended to the utmost, and protruded beyond the margin 

 of the cloak : when at rest, they are kept concealed under this 

 their penthouse. It swims easily in a reversed position at the 

 surface, the foot being then made slightly concave. The form 

 of the foot is variable ; for sometimes the animal will expand 

 it until it becomes almost circular, or extend it until it forms 

 an oblong square obtusely pointed behind. When alarmed, 

 the body is contracted so that the edges of the cloak meet 

 together on the ventral aspect, and the foot is greatly narrowed. 

 The eyes are proportion ably large, and are visible from below, 

 shining through the transparent skin. 



The synonymes, so far as I am in a condition to ascertain 

 them, are, — 



Lamellaria tentaculata Montagu, in Lin. Trans., xi. 186 , pi. 12. figs. 5, 6.; 

 Bulla tentaculata Turton, Conch. Diet., 25. ; Sigaretus tentaculatus 

 Flem., Brit. Anim., 360. : 



and, it is curious enough, not one of all the three can be re- 

 tained. Lamellaria is preoccupied in botany ; and neither 



