REPORT ON THE NUDIBR AN CHI AT A. 
17 
The relative proportions of the parts of the body were quite typical. The colour 
has been already described. 1 The dorsal papillae of the two first groups are arranged in 
arches, the first of which was the largest and appeared to be complete, containing from ten 
to eleven papillae ; one of these papillae is very large, its length about equalling the 
diameter of the body of the animal ; at the side of this another rather large papilla, and 
the papillae following this decrease in size towards the ends of the arch. The second arch 
contains a smaller number of papillae (6 to 8), of which one is much larger than the others. 
Behind this comes a short row of two small papillae, but no trace of a fourth group could 
be detected. 2 The arrangement of the papillae and their form has been already described 
by me. 
The viscera are conspicuously apparent through the walls of the body. 
The nervous system has been thoroughly investigated by myself 3 and by Vayssiere 
and v. Jhering. 4 According to the last-mentioned author, the central nervous system 
closely resembles that of Phylliroe, the “ cerebro-pleural (cerebro- visceral) ganglia ” of 
my monograph being in reality equivalent to the cerebral ganglia only of other molluscs, 
and the ganglia described by me as “ pedal ” being really composed of the fused pleuro- 
pedal (viscero-pedal) ganglia. This view I do not believe to be correct. The upper 
ganglia show an indistinct division into two parts, and since the development of the 
foot of Glaucus is not inferior to that of many other iEolidiadse, or indeed of many 
Nudibranchiata in general, there is every reason to suppose that it agrees with these 
latter in possessing isolated pedal ganglia. According to von Jhering and other authors, 
all the commissures originate from the lower ganglia. This statement is not correct ; the 
viscera] commissure, at any rate, can be traced up to the lower side of the upper ganglia. 
The otocysts contain from 20 to 28 otoconia. The eyes typical. 
The bulbus pharyngeus measures 1‘5 mm. in length. The mandibles typical, the 
masticating edge (PI. XIV. fig. 16) being provided with a single series of pointed denticles, 
the largest of which measure ‘0125 mm. The radula has twelve teeth; farther back sis 
developed and two undeveloped teeth. Each tooth has from seven to eight denticles. 
The digestive system, renal organ, and urticating bag, have been already fully described 
by me. The latter organ is filled with urticating cysts and free urticating elements of the 
usual form, among which are several larger ones of a peculiar character. 5 — The genital 
system I have described elsewhere; the penis is typical in shape, having at its extremity 
a dirty yellowish coloured hook, measuring about 0‘18 mm. in length. 
1 Bergh, Bidr. til Kundsk. om iEolidierne, loc. cit., 1864, p. 256. 
2 In small specimens (6 to 7 mm. in length) previously examined hy me (loc. cit., p. 259), there was invariably a small 
rudiment of a fourth group, sometimes represented merely by a single papilla. In very small specimens (2 to 3 mm. in 
length) there was no trace of a fourth or even of a third group (pp. 283-284). 
3 Bergh, loc. cit. 
4 II. v. Jhering, Vergl. Anat. d. Nervensyst. d. Moll., Leipzig, 1877, pp. 183-185. 
6 Bergh, loc. cit., p. 276, Taf. vi. fig. 29 **. 
(ZOOL. CHALL. EXP. PART XXVI. 1884.) Cc 3 
