82 E. A. ANDREWS. 



The setse are short but form very long rows. Those of the 

 base extend along the neck far up onto the external mass and 

 those of the median face run nearly its whole length. There are 

 also some additional setae upon the dorsal face near the tip as 

 seen in Fig. 8. 



In following the groove (Fig. 7), we find that after it passes 

 the very slender and insignificant spatula it turns ventrally to end 

 on a blunt protuberance indicated in the dotted area in Fig. 7. 

 There is left a large protruding mass external to the spatula, 

 which is indicated in parallel shading, and which is evidently 

 part of the median mass that does not extend to the very tip of 

 the groove. Thus the tip of the stylet is bifid ; the blunt part to 

 the right in the figure is the canula and the part to the left is a 

 sharp blade formed from the median mass beyond the spatula 

 and this we will call the scalpel, from its shape and its probable 

 use in opening the very firmly closed and constricted slit of the 

 annul us in the females of this species. The scalpel is apparently 

 well placed to cut open the orifice of the annuius (see /, Fig. 24). 



The character of this condensed terminal region is better seen 

 in the enlarged view of the external face of the tip (Fig. 8). 

 The scalpel, to the right, bears the above-mentioned setae at its 

 base and has a sharp convex edge. 



It is set off from the canula by a depression. The canula itself, 

 as seen behind the outer parts of the setse, is slightly bifid in this 

 preparation but in dried specimens it ends with a terminal orifice. 

 While the stylet has two elastic tips the canula ( C) and the 

 scalpel {Sc) they are so near together that both might readily 

 enter the orifice of the annuius. 



On cutting sections of this unusual stylet we find that the groove 

 has its bottom cut off by a shelf (Fig. 9), just as in the other 

 species. But the tubule so formed is so minute and so deeply 

 buried that it is easily overlooked. A section (Fig. 9) taken 

 near the base of the spatula at ^ (Fig. 7) shows the median mass 

 so extended as to make a sharp blade, the scalpel (Fig. 8). 

 And moreover the shelf that arises from the external mass, at 

 this level, points away from the median mass, so that the section 

 is not readily compared with that of C. virilis (Fig. 13). In sec- 

 tions the horny shelf can be traced down from the free edge of 



