142 PROCEEDINGS OF THE MAXACOLOGICAL SOCIETY. 



integuments are thin; the mantle-edge thickens. The texture and 

 external characters are as described by Mr. Crossland. The pits and 

 ramifying lines are still visible, but not conspicuous (Fig. 4). The 

 openings of the rhinophores and branchiae are not stellate or markedly 

 tuberculate. The branchial pocket is shallow, and the lateral branchiae 

 can be counted as either six or eight, the third and fourth plumes 

 on either side being united at the base (Fig. 4). There is generally 

 a small unpaired plume in front, opposite the anal papilla, which 

 completes the circle behind, so that the whole number of plumes seen 

 protruding from the pocket is nine. 



The labial armature consists of two greenish plates, composed of 

 short, slightly curved rods, with rather swollen tips. These tips form 

 a mosaic. 



The radula is fragile and easily becomes confused. There are about 

 25 rows, with a formula reaching at least 10 -}- 35 . . 35 + 10. 

 At the outer ends of each row is a bunch of long, thin teeth (Fig. 5^) 

 lying very close to one another, so that they are difficult to count. 

 There are, however, at least 10 in the bunch or sheaf, and perhaps 

 considerably more. The other teeth (Fig. 5a) are comparatively low, 

 hamate, with long bases. The rhachis is narrow, and the innermost 

 laterals of the two sides almost cross one another. 



The intestines are whitish. The oesophagus is moderately long, but 

 varies somewhat in different specimens. In all cases, however, it 

 enters the liver without any external dilatation, and the stomach 

 is wholly within the liver. 



The hermaphrodite gland is ample, forming a thick, white layer over 

 the liver There is a large mucous gland, gelatinous, colourless, and 

 semi-solid externally, hard and yellow in the inside. The spermato- 

 theca is large and roughly spheiucal; the spermatocyst small and 

 elongate. No armature of the glans penis was discovered and no 

 prostate. 



This species is very nearly allied to the Geitodoris found at Plymouth 

 (v. Eliot, I.e.), which is probably identical with the animal called 

 Doris planata by Alder «& Hancock. It is not improbable that the 

 African and British forms are merely varieties of one species, the 

 tropical specimens being, as is natural, larger and more brightly 

 coloured. But I have thought it safer to describe them under 

 a separate specific name. 



Peltodoris, Bergh. 

 This genus differs from Discodoris only in not having a labial 

 armature, and would perhaps be better regarded as a subgenus, for 

 the armature in question is merely a collection of small rods which 

 strengthens the labial cuticle, and, unless it is much developed, is not 

 a conspicuous or important character. The following species have 

 been described : — 



1. P. atromaculata, B. Mediterranean. 



2. P. cruets (Oersted). West Indies. = P. Sauvagei, Bochbr., 



Cape Verd. 



3. P. Mauritiana, B. Mauritius. 



