S4 W. BLAXLAND BENHAM. 



I suggest the names Drepanidotgenia minuta and 

 D. apterygis for these two new Cestodes. 



I. Drepanidotsenia minuta^ n. sp. 



The smaller of the two Cestodes occurs in the duodenum ; 

 when killed it measures from an eighth to a sixteenth of an 

 inch in length, with a breadth of one twenty-fifth of an inch. 

 The scolex is followed by about ten or twelve apparent pro- 

 glottids, all of which are of the same breadth. The whole 

 strobila thus is nearly rectangular, with the exception of 

 the curved scolex. In horizontal section — section, that is, 

 in a plane parallel to the broad surface of the worm — it 

 shows a maximum of eighteen proglottids, of which the ante- 

 rior ones are very short, and do not show on the surface ; 

 these are preceded by an unsegmented area or neck, equal 

 in length to about the first half-dozen proglottids. 



In compressed specimens, mounted entire, the delimita- 

 tion of the scolex is obscure (fig. l),but in specimens floating 

 in spirit the anterior proglottids are frequently but not 

 invariably narrower than the hinder margin of the scolex 

 (fig. 2). This appears to be connected with the state of con- 

 traction of the pai'ts concerned, for most specimens have 

 the shape shown in Plate 7, fig. 1. The proglottids do not 

 overlap one another to any noticeable degree. 



Of the eighteen proglottids, the last alone contains ripe 

 eggs, with fully formed onchosphere in their envelopes. This 

 last proglottid readily falls off, so that in many instances no 

 complete eggs occur. In the four or five penultimate pro- 

 glottids the generative organs are more or less fully formed, 

 but the gi^eater number show only traces of the gonads. 



The isolated proglottids are usually U-shaped, and rather 

 larger than the terminal proglottid of the strobiJ a (fig. 7) ; 

 but in other cases they agree in size. Frequently during the 

 process of mounting a strobila a proglottid would separate. 

 The peculiar form assumed by the isolated proglottid, brought 

 about by the unequal contraction of the muscles, seems to 



