203 



Body contracted a little behind the mantle, ending in a broad 

 bifid tail, the divisions equal, ovate, resembling somewhat the 

 "flukes" of a whale. 



Mouth circular — situated in front, without teeth or liorny jaws, 

 or even a denticulated tongue, the food being apparently swallowed 

 whole, (though none was found in the specimens) openuig du-ectly 

 into a large stomach occupying the anterior third of the body, from 

 which a short S-shaped mtestine passes through the Hver, ending 

 at the cloacal opening under the middle of the tail. In this part 

 of the canal are three corneous bodies, probably intended for 

 reducing the harder portions of its food by grmding. 



Branchia single, plume-shaped, rising on the right side of the 

 anus and curving over it towards the left, being completely covered 

 by the tail. No shell. 



Spec. Ohar. — Vinous-purple, ornamented with numerous rounded 

 or oblong yellow spots : mner surface of enveloping folds, flesh- 

 color. Edge of mantle and taU orange, with a narrow band of rich 

 blue, forming a scolloped edgmg alternately blue and gold ; a row 

 of alternating spots of the same along the centre of the ear-like 

 processes. Under surface of tail deep purplish-blue. Whole sur- 

 face perfectly smooth and shining. Eyes white with a black pupil. 

 Length, 3^ inches ; breadth, | inch. 



This beautiful animal inhabits muddy parts of San Diego Bay, 

 where I found it not uncommon in spring. It creeps among the 

 grasses slowly and looks hke a large caterpillar. Though without 

 any apparent means of escape or defense, it seems httle molested 

 by other animals. As an o])ject for study in an aquarium for the 

 investigation of the metamorphoses it doubtless vmdergoes, from the 

 egg to its perfect state, it would be highly mteresting. It is more 

 highly organized than any other genus of Opistho-hranchiata, 

 resembhng Aplysia more nearly than any other, and probably 

 carnivorous or a carrion-eater. 



Pleuropht/Uidia Calif orniea, n. sp. 



Sp. Ch. — Form ovate, obtusely rounded in front, subacate pos- 

 teriorly, back nearly smooth, gray, with about fifteen slightly 

 elevated white stripes, arising alternately from either end, and inter- 

 locking regularly together at various distances, each terminating 

 m a sharp, bluish point. Broad expanded veil black, with a white 

 margin. Low^er tentacles very small, (eyes none ?) upper tentacles 

 on vertex. Foot narrower than mantle, ovate, sharp behind, later- 

 ally expanded into a narrow membrane. Color reddish ; branchiae 

 of a darker shade. Length, 2i inches ; breadth, 1 j inches. 



