242 I. IK EDA : 



spacious cavity, the stomo-rhynchodaeum, which opens to the exterior 

 at a position slightly ventral to the extreme tip of head. The true 

 mouth leads posteriorly into the oesophagus, which is followed by the 

 stomach, the pyloricus, and the intestine successively. From the 

 dorso-lateral corners of the pyloricus there arise two long anteriorly 

 directed caeca (cc, fig. 3), which reach up to the brain (tig. and 

 vg.). These c;cca seem to be structurally identical with the intesti- 

 nal ca^ca, which occur along the entire length of the intestine and 

 number about 90 on each side. 



As before indicated, the rhynchocœl may correspond in its range 

 approximately to two-thirds of the body-length. This is the case with 

 the adult. But in the younger specimens, say in those just hatched, 

 the cavity is relatively much longer, occupying about nine-tenths of 

 the body-length. As the growth advances, the rhynchocœl also grows 

 in length, but somewhat more slowly than the entire body ; so that, 

 at a stage when the latter has attained a length of 10 mm., the 

 former is about four-fifths as long, and finally in full-grown individuals 

 its length is equal to about two-thirds of the body-length. 



As to the morphology of the proboscis-stylets (chief and accessory) 

 and of the stylet-sac, the present species more nearly agrees with the 

 description given by Böhmig from Stichostemma gracense than that 

 by Montgomery from St. eilJiardiP One point worth mentioning is 

 the fact that, so far as my observations go, the number of accessory 

 stylets in each sac or " acanthocyst" is 3. 



One peculiarity of the present species consists in the fact that 

 the proboscis-nerves are not definitely fixed in number, being either 9 

 or 10 according jto individuals. I have not examined enough speci- 

 mens to be able to decide which of the numbers Ì5 the predominant. 

 Nevertheless, it may safely be stated that this variation in number is 

 not due to secondary separation or coalescence of the nerves. 



1) Montgomery, T. II., Stichostemma Eilhardi now gen., nur. sp. Zeitochr. f. Wiss. 

 Zool., Bd. 59, 1895. 



