.REPORT ON THE NUDIBR AN CHIATA. 
39 
glands scattered thickly about and arranged in groups. The fibres and lamellae of the 
interstitial connective tissue showed the usual structure. 
The mouth tube was as usual. 1 The buTbus pharyngeus of the ordinary form, a little 
depressed, and about 6 mm. long by 5 mm. broad and 4 mm. high. The musculi 
retractores superiores (mediani and laterales) as in other species ; 2 they belong properly 
to the mouth tube. The labial dish is large and very thick ; it is quite similar to that 
of other species ; 3 at the anterior margin the labial plates are of a dirty yellow colour, 
above and below they nearly meet in the median line, the surface is finely striated; 
their length is 3'5 mm., breadth not quite 2 mm. 4 They displayed along the middle of 
their length the usual rows of small scales (PL VII. fig. 15), measuring about "007 mm. 
in breadth ; at the anterior margin there were a number of small columns, about - 04- , 08 
mm. in length. 5 Behind the labial disk is a large muscular mass upon the fore part of 
the mandibles, consisting of the two usual layers.® Behind this again are the mandibles 
(PL VIII. figs. 2, 3), of a chitinous yellow colour, deepening to brownish-black upon the 
masticatory edge; each measures 3‘5 mm. in length, 2'25 in breadth, and * 5 mm. in 
height. In shape they resemble those of other Bornellce ; on the inside beneath the 
hinge and near the masticatory edge, there is a triangular excavation (fig. 3, b); the 
masticatory edge (fig. 2, b) is roundly indented ; there is no masticatory process. The 
mouth slit is narrow, the accessory buccal cavities small. The buccal cavity is narrow 
and entirely occupied by the high compressed tongue. The tongue is provided with a 
narrow raclula, brownish-yellow in colour, and not excavated along the rhachis ; it is made 
up of seventeen rows of teeth on the high anterior margin, and three on the shorter 
upper margin ; 7 farther back, within the stout somewhat longer radula-sheatli, there 
were nineteen developed and two undeveloped series of plates, making a total of forty-one. 
The most anterior (lowest) row (of the tongue) is only represented by the median tooth; 
the next series consists of a median tooth, and one lateral tooth on one side, and seven on 
the other ; the succeeding rows are more complete, the first fourteen row T s still incomplete 
and provided with a considerable number of worn-out teeth (Pl. VII. fig. 16). The 
median teeth (PL VIII. figs. 4, 5, 6, 7, a) are reddish-yellow, almost chestnut in colour ; 
the lateral teeth clear yellow, darker at the base. The breadth and height of the median 
teeth at the middle of the tongue were each about T2 mm., and those, situated posteriorly, 
appeared to measure about the same. The length of the hook of the lateral plates 
averages about T mm. The median teeth (figs. 4-7) have the usual form; on 
1 Bergh, loc. cit., Taf. xxxvi. figs. 9, c, 10, c. 
2 Loc. cit., figs. 9, act, 10, a — fig. 9, bb. 
3 Loc. cit., p. 294. 
4 Loc. cit., Taf. xxxvi. figs. 11-14,/. 
5 A vast quantity of cnidse were adherent to the labial disk. 
6 Bergh, loc. cit., p. 293. 
7 The rhachis of the tongue was covered with a greyish inass, which proved to he made up of densely 
entangled masses of cnidse. 
