378 Mr. H. N. Moseley on a Young 



action of glycerine failed, and the specimen perished. The 

 trawl came up late in the evening, when only an hour of day- 

 light remained ; the examination made was thus a hasty one. 



The animal showed the same feeble pulsating movements 

 which had been shown by the adult. 



The external gelatinous investment of the body was per- 

 fectly transparent ; and none of the peculiar corrugations of a 

 thin superficial epidermic layer were visible as in the adult 

 specimen. The contours of the body were well preserved, 

 including those of the hinder portion, which was broken in 

 the specimen before obtained. 



The fore part of the body is wide, with rounded margins ; 

 the posterior narrowed, with a series of indentations on its 

 margin corresponding to the successive pairs of diverticula of 

 the digestive tract. At the extreme hinder termination of the 

 body is a shallow notch, at the bottom of which is the anus. 



The mouth, which is a simple opening at the apex of a 

 small, short, conical protuberance, was situate just in front of 

 the nerve-ganglia on the ventral surface of the body (it is not 

 shown in the figure, which represents the animal from the 

 dorsal aspect). The central canal of the digestive tract termi- 

 nated in front in a wide rounded blind end, and tapered gra- 

 dually to the anus at the posterior end of the body. 



The lateral diverticula in this young specimen were evi- 

 dently in an immature condition ; and the successive pairs 

 showed successive stages of development, the most anterior 

 being the most fully formed. This most anterior pair is the 

 only one which shows a commencement of ramification at the 

 peripheral extremities. The ramifications, so ample and well 

 marked in the adult worm, are seen here to be developed as 

 cascal buds from the outer ends of the long diverticula. The 

 diverticula themselves, of which five pairs were present in 

 the young specimen here figured, arise, as can be seen 

 from the figure (PI. XI. fig. 1), as simple lateral buds 

 from the central digestive tube. These buds gradually in- 

 crease in length, their peripheral cascal ends being always 

 larger than the tubes connecting these with the central digestive 

 tract ; and eventually these cascal ends give off buds and form 

 ramifications. A slight enlargement in the rectum situate just 

 anteriorly to the anus, and shown in the figure, probably repre- 

 sents the spot where a sixth pair of diverticula were about to 

 bud off from the digestive tube. The diverticula, with the ex- 

 ception of the first pair, were not placed exactly opposite one 

 another, the right diverticulum in each pair being situate 

 anteriorly to the corresponding left one. 



The digestive tract was filled with a dark reddish brown 



