160 s. GOTO. 



sections as a dark line with indistinct l/orders, sepai'ating the epider- 

 mal from the muscular layer. It is also much thicker than the 

 cuticula. The total thickness of the integument, with the cuticula 

 and hasement membrane taken together, is about 0.004 mm. 



-, It has already been mentioned that little conical elevations exist 

 here and there on the surface of the body. These are more abundant 

 on the ventral than on the dorsal side, and are entirely absent in the 

 posterior half of the body. They are simple elevations of the epider- 

 mis with an almost homogeneous mass of connective tissue under it. 

 Here the nuiscular layers do not touch the basement membrane, but 

 p:!ss straight on ; so that these elevations are somewhat subject to 

 changes of form. I have represented one of them in section in 

 Fig. 7 (PI. XXII). As will be seen, they are pointed at the end. 

 A very similar structure has been described in Sphijranura Osleri,^^ 

 where it seems to act as a sense organ. But although I directed my 

 special attention to the point, and applied the highest magnifying 

 power at my disposal (Zeiss Imm. L.), I could not discover any 

 canal opening at the apex, or any hair-like projection, or any fibrils 

 such as have been observed in the above-mentioned species to supply 

 these conical bodies. 



II. The Muscular System. 



The muscular svstem is const inued bv the muscular wall of the 

 body, the dorso-ventral muscles, and the muscles pertaining to the 

 various organs. 



The muscular layer of the body consists of three layers. These 

 are, counted from outside inwards, the circular, the diagonal, and the 

 longitudinal muscles. The circular fibres run everywhere immediately 



1) R. Wriglit and Macallum — Sphyrauura Osleri : a Coutribuiiou to American Hclmin- 

 thology- Journ. of Morph. Vol. I. 1887. p. 9. 



