345] PSEUDOPHYLLIDEA FROM FISHES—COOPER 57 



circular and longitudinal muscles in the scolex, which are merely extensions 

 of the cuticular muscles of the neck region, are not nearly so strongly developed 

 as in C. truncatus. There is, however, in the neck region, particularly in its 

 anterior portion, a series of outer longitudinal muscles which, altho situated 

 in transections among the outer clear ends of the subcuticular cells and very 

 close to the longitudinal cuticular fibres, are nevertheless quite distinct from 

 the latter. At the base of the scolex they pass inwardly between the cells of 

 the subcuticula and continue farther towards the anterior border of the funnel 

 than do the inner or main longitudinal fibres. Posteriorly they diminish con- 

 siderably in number but may readily be seen in the mature proglottides. 



The nervous system is arranged in general as in C. truncatus; but the 

 longitudinal trunks are only 26/x thick by 13 wide (0.345mm. according to 

 Kraemer). In the neck they are scarcely enlarged to form gangha, such as 

 shown in Kraemer 's Fig. 5, but each is divided into two distinct dorsoventral 

 halves which gradually diverge as they pass on into the scolex to form four large 

 nerves. There is no single transverse commissure connecting the main trunks 

 behind the funnel of the scolex but instead a number of fine cross-connections 

 which are often difficult to make out satisfactorily. 



As regards the excretory system there is an inconstant number of longi- 

 tudinal vessels in transection, evidently more than the six of C. truncatus, which 

 do not occupy definite positions but anastomose freely with each other especial- 

 ly in the lateral portions of the medulla. In the scolex these vessels are smaller 

 and the anastomoses are much more numerous, while posteriorly at least two 

 pass into a quite irregularly shaped terminal vesicle, which, however, in the 

 light of Wolf's (1906) findings cannot be considered to be z, true terminal 

 excretory vesicle. As above stated, foramina secundaria are quite numerous 

 in the cuticula. 



The reproductive organs appear quite close behind the neck, the vitelline 

 follicles being situated from 1.3 to 2.3mm. from the anterior border of the 

 scolex, and the first cirrus-sacs from 1.6 to 2.2mm. From 10 to 20 sets of 

 genitaUa were observed for this species. These follow each other closely and 

 are not separated by any septa or other boundaries, the vitelUne follicles being, 

 in fact, strictly continuous from proglottis to proglottis. The openings of the 

 cirrus-sacs vary from 0.45 to 0.75mm. apart, but as pointed out by Kraemer, 

 these measurements are of little diagnostic value on account of the different 

 states of contraction. As in C truncatus the reproductive openings are all on 

 one surface of the proglottis but alternate as a unit irregularly from one surface 

 to the other. There is, however, a strong tendency for them to lie all on the one 

 face of the strobila. This alternation also involves the ovary, the isthmus of 

 which is arbitrarily considered in the cestode to be ventral. It usually lies 

 on the same surface as the reproductive openings, so that when the latter passes 

 to the opposite surface it moves accordingly. This alternation of the openings 

 has, of course, been knowTi ever since Pallas described Taenia truncata in 1781, 

 but, so far as the writer is aware, no one has dealt with the relations between 

 the openings and the ovary noted here. Concerning this matter Kraemer 



