INDIAN NUDIBRANCHIATE MOLLUSCA. 139 
hyaline variety is represented among Mr. Elliot’s drawings, which seems to be Kelaart’s 
species, but is assuredly the young of M. fimbriata. 
This species is tolerably frequent, but is difficult to preserve entire on account of the 
deciduous nature of the processes. It has a delicate and gelatinous appearance when 
alive. 
Two or three mutilated specimens are in the collection. 
M. fimbriata differs from the M. rosea of Rang in the form of the branchiz, which in 
the latter are claviform, with rounded tops, and beset with stout tubercles. The body 
of M. rosea likewise appears to be smooth. 
Family DENDRONOTIDE, Alder & Hancocs. 
Genus Bornetta, Gray. 
Body compressed, without cloak. Tentacles two, retractile within branched sheaths. 
Head with two branched or fimbriated appendages. Branchize plumose and papillose, 
arranged on foot-stalks, in single series on each side of the back. Anus lateral. Tongue 
narrow, with a large, broad, denticulated, central spine, and several smooth lateral spines 
on each side. 
The anatomy of this genus confirms the opinion (that might be inferred from its 
external characters alone) of its close relation with Dendronotus. The organic structure 
in the two forms agrees throughout in almost every particular. 
The buccal organ is rather large, and is armed with corneous jaws and a spiny pre- 
hensile tongue, which is supported on the ridge of a wedge-shaped muscle that rises 
from the floor of the mouth. The armed membrane is supplied with from thirty-eight to 
forty transverse rows of spines, a large broad central spine with the margins denticu- 
lated, and on each side of it nine smooth comparatively slender ones. Two dendritic 
or folliculated salivary glands pour their secretion through delicate ducts into the 
posterior extremity of the buccal organ, one on each side of the cesophagus. 
The cesophagus is rather long and slender: it opens into the anterior extremity of 
the stomach, which is well defined, rather large, and of an oval form. The latter has in 
the interior a broad transverse belt of soft, recurved, pointed papillz, arranged in close- 
set longitudinal rows. The hepatic duct enters just in front of this belt ; and a large 
fold of the mucous membrane, which passes from the intestine, advances to its posterior 
margin. It is difficult to say what is the function of this peculiar papillose structure, 
though, from its position, it may possibly be a modification of the supposed pancreatic 
organ in Melibe. 
The intestine is extremely short : it issues from the posterior extremity of the stomach, 
and goes to the right side of the animal, where it terminates in an anal nipple between 
the first and second branchial tufts. 
