608 TRANSACTIONS ELVERPOOI “BIOLOGICAL SOCIETY. 
of the above writers have done, its identification with an 
adult form still remains an unsolved problem.* 
Nectosoma.—tThe earliest stage obtained was 
700% long by 200” broad. It shows a posterior unseg- 
mented region preceded by about ten somewhat. indistinct 
segments. The first of these 1s provided with a tuft of 
long straight setae, and the others with shorter but other- 
wise similar ones; no neuropodial setae are present as yet. 
The body-wall is thin dorsally, but thicker ventrally. The 
gut is broad, and contains a (yolky ?) substance of finely 
eranular appearance and faint staining properties with 
borax-carmine. No food-material from the exterior has 
been seen in the gut in the earlier stages. The head is 
rounded in front, and after fixation is almost always 
ventrally flexed. Young specimens examined alive bore 
two pairs of red eye-spots on the dorsal surface of the 
head, the inner pair being situated somewhat behind the 
outer pair. They also showed a spot of opaque yellow 
pigment at the base of each tuft of setae; these spots were 
smaller towards the anterior end of the larva than they 
were towards the posterior end; and a line of minute 
specks of the same opaque pigment was found to extend 
across each segment between the spots situated on either 
side of it. 
The larvae elongate by the continuous development 
of new segments, and the boundaries of the old segments 
become more clearly defined. The neuropodial setae soon 
appear, the first of each tuft to develop being very much 
stouter than the rest, which resemble those already present 
**Dr. Allen has called my attention to the fact that Claparede 
himself subsequently described (Zezts. wiss. Zool., XXV., 1874— 
included in a paper by Ehlers) fragments of a worm which he 
recognised as the adult of this larva, and for which he founded the 
genus Poecilochaetus, a genus separated from the €pionidae by Mesnil 
_and placed in his new family Disomidae. Dr. Allen has since fully 
described a species of Poecilochaetus (Quart. Journ. Mier. Ser., XUVITL., 
1904). 
