1905.] NATURAL SCIENCES OF PHILADELPHIA. 391 



somites VIII to XII, where it resembles the condition figured by Stole 

 for Bothrioneuron. 



None of the specimens is mature, so that the reproductive organs are 

 not fully developed, and further study may require some modification 

 of the following account, especially in what relates to the penis sheath, 

 prostate glands and extent of the sperm sac and ovisacs. Thetesteshave 

 the usual location in X, but remain small in all of the specimens sec- 

 tioned. A single sperm sac (which may be double anteriorly) reaches 

 from the septum ^ as far as XIII or XIV, but probably much farther 

 in fully mature worms. It includes long loops of the lateral blood-ves- 

 sels of X, and is itself enclosed in the ovisac which arises from the 

 succeeding septum. 



The male efferent apparatus is shown semi-diagrammatically in 

 fig. 16. The large, few-celled sperm funnel is so distorted by pressure 

 from the intestines, blood-vessels, sperm sac and the septum ^j that 

 no accurate drawing could be made. After penetrating the septum ^ 

 the vas deferens forms several close loops between the sperm sac and 

 the intestine, and then, after curving round the former, takes a more 

 open com-se in the posterior part of the segment before opening into 

 the atrium. The entire atrium is about one-fourth the length of the 

 vas, consists of a small fusiform sperm reservoir receiving the vas at 

 one end and the rather small prostate gland on one side. At the other 

 end it passes into a scarcely distinct ductus ejaculatorius of about 

 equal length, which in turn passes into the summit of the simple erect 

 penis sac. The latter is about as long as the preceding two parts of 

 the atrium combined, is of nearly cylindrical form, has no special nor 

 well-developed muscle sheath and contains the soft filiform penis, 

 which in these specimens lacks any chitinous sheath. The free end of 

 the retracted penis is received into a small bursa which is provided with 

 a circle of small glands and opens at the position of the missing ventral 

 setse of XL The ovaries are in XI, but the oviducts have not been 

 detected. As mentioned above, an ovisac arises from ^^^ and, receiv- 

 ing the sperm sac and a pair of vascular loops, extends to about XV or 

 XVI. 



The spermathecse (fig. 18) open just behind the ventral or copulatory 

 setse of X. They are probably not fully developed in any of the speci- 

 mens. In those of largest size they have a length about equal to one- 

 half the diameter of the body, are more or less club-shaped with a 

 simple duct forming about one-half the length, and a more or less dis- 

 tinct pouch, which may be elongated or spherical and pass gradually 

 into the duct or be sharply defined. No distinct spermatophores are 



