REPOET ON THE NUDIBR AN CHIAT A. 
35 
The clorscd margin is prolonged into several 'papilla, which at the free upper end are 
divided into several (4-2) points, and at the base bear several tripinnate branchiae, which 
on the outer side are sometimes protected by special finger-shaped processes. The anus 
is latero-dorsal in position, and lies just in front of the second dorsal papilla. The foot 
is small and rounded anteriorly. 
The bulbus pharyngeus is not large, and is to a great extent formed by a powerful 
muscular mass as in the Pleurophyllidiadre and Phylliroidse. The thick labial disk has 
a special scale-like armature. The mandibles are large, powerful and compressed, without 
any masticatory process. The tongue is high; its armature consists of a median tooth, 
which is not large, and number of lateral teeth, the latter being always smooth, the 
former occasionally denticulate. The stomach has two divisions, the hinder of which is 
provided with a series of chitinous spines in its interior. The gut is short. With the 
exception of one form ( Bornella exceptci), all the species of this genus which have been 
hitherto examined possess a branched liver which sends prolongations into most of the 
papillae, entering them more or less at the base. The penis has an oblique girdle of 
straight or curved thorny processes. 
The genus Bornella seems to be confined to the tropics, and has always been found 
among Fucoids ; of its habits Adams and Pease have given some account ; the animals 
are said to creep “ briskly ” about over the surface of Fucoids ; and sometimes to swim 
freely in the water by lateral movements of the body. 
Only the following species 1 have been hitherto described 
1. Bornella digitata (Adams and Peeve), Bergh, 
Indian Ocean. 
2. Bornella calcarata (Morch), Bergh. 
Atlantic Ocean. 
3. Bornella arborescens (Pease), Bergh. 
Bergh, Neue Nacktschnecken d. Siidsee. II. Journ. d. Mus. Godeffroy, Heft vi., 1874, 
pp. 96-102, Taf. i. figs. 3-4; Taf. ii. figs. 30-33 ; Taf. iv. figs. 1-28. 
4. Bornella excepta, n. sp. 
Pacific Ocean. 
5. Bornella adamsii, Gray ? 
Indian Ocean. 
6. Bornella hancockana, Kelaart ? 
Indian Ocean. 
1 Bergh, loc. cit., pp. 288-289. 
