122 Description of New and Little known Species of 



This very beautiful species is found in deep water. It 

 occasionally buries itself in sand, with only the head and 

 tentacles exposed, and lies for hours in this position. 



Order. Tectibranchiata. 



Animal usually provided with a shell both in the larva 

 and adult state ; branchiae covered by the shell or mantle ; 

 sexes united. 



Fam. Pleurobranchim:. 



Genus. Pleurobranchus. Cuv. 



Animal oblong, fleshy, convex above with a very large and 

 overspreading mantle. Foot large, equally outspreading, and 

 thus leaving a wide canal all round the body. Head distinct, 

 furnished with a veil, uniting on each side with the borders 

 of the foot, and with two tubular tentacles, which are split 

 anteriorly ; mouth at the extremity of a proboscis ; branchiae 

 composed of a double row of lamella, forming a plume on the 

 posterior right side, between the mantle and the foot. Anus 

 carried by a small tube behind the branchiae, Organs of 

 generation in front. Shell sometimes rudimentary, mem- 

 branous, with a tolerably distinct apex hidden in the thick- 

 ness of the mantle. — Woodward. 



Pleurobranchtjs Citrinus ? Rlippel 4 



Orange reel ; mantle darker than the other parts of the 

 animal, and speckled with whitish spots. About 1 inch in 

 length. Ova reddish, in circular broad coils, 



