532 NUDIBRANCHIATA OF THE SCOTTISH NATIONAL ANTARCTIC EXPEDITION. 
The edge is smooth, and there seems to be no masticatory process. The radula is 
colourless and transparent. Seen from above, the median teeth (fig. 18) appear as 
simple, straight, pyramidal spines, rising from broadish bases; seen from the (fig. 17) 
side they are slightly bent downwards towards the tip, and somewhat resemble the 
teeth of Favorinus. They are quite smooth. The first laterals (fig. 19) are rather 
stouter than the others, but not of a different shape, as in Tritonia. The remaining 
laterals (fig. 20) are very long ahd thin, sometimes almost like filaments. They vary 
somewhat in shape: those nearer the rhachis are more distinctly hamate, those in the 
outer half of the row have a wavy or almost straight outline. They are difficult to 
count, as they seem to lie in sheaves, but the number on each side does not much 
exceed thirty at most. 
The short and broad cesophagus leads straight into a rather small membranous 
and fragile stomach, almost entirely covered by the liver, and with no trace of 
plates. The liver is of a pale yellowish colour, covered with a thick layer of the 
hermaphrodite gland, which is of much the same hue, but still lighter. The albumen 
and mucous glands are greyish and of moderate size. The spermatotheca is yellow, 
roundish, small, with a long duct. The vas deferens not much convoluted. The verge 
is long, pointed, not armed ; as preserved, it is curved at the end. 
Scyllaea pelagica, L. 
Ten specimens, captured on Ist July 1904, off floating gulf weed, 33° 53’ N., 32° 27’ W. 
They vary in length from 7°5 mm. to 13°5 mm. The colour is semitransparent 
white, with occasional minute spots of opaque white and a certain amount of yellowish- 
brown pigment, found chiefly on the margins and bases of the appendages, and differing 
in intensity and quality in the different individuals. 
In some specimens there is nothing that can be called a caudal crest, the tail being 
merely rudder-like, and not raised above the level of the dorsal surface; but this 
peculiarity is not accompanied by any anatomical variation from the type, and passes 
into the normal form through intermediate stages. 
