BY N. A. COBB. 151 



represented in the accompanying cuts. The manner in which this 

 peculiar arrangement is made of service to the animal may be 

 thus reasoned out. The head having been thrust out and the lips 

 having obtained a purchase, the spear is moved forward by con- 

 tracting the length of the body by means of muscles attached to 

 the body wall inside the head. This contraction results in an 

 infolding of the skin of the head. This reasoning is exactly in 

 harmony with the usual position of the spear in Dorylaimus, for 

 it is well known to be situated well forward, being in fact often 

 normally a little exserted. Attention might also be called to the 

 sinuous condition of the narrow anterior portion of the oesophagus 

 as being also in harmony with the above view. The apparent 

 disproportion between the length of the neck and that of the 

 oesophagus might be thus explained. 



We return now to Onyx. Passing from the oesophagus the food 

 enters the intestine through a narrow cardia. The connection 

 between the oesophagus and the intestine is unusually small, the 

 diameter at the cardiac collum being not more than a sixth as 

 great as that of the base of the neck. The thick wall of the 

 intestine is built of a single layer of large cells, which are of such 

 a size that half-a-dozen side by side make up a circumference. 

 The width of the intestine where it is the sole occupant of the 

 internal cavity is not far from four-fifths as great as the width of 



off than its posterior. The distinct lateral fields are of a lively brown colour 

 and appear to terminate posteriorly in pores near the rounded terminus of 

 the tail. Anteriorly they become narrower and apparently cease altogether 

 in the neighbourhood of the nerve-ring. This latter is oblique and as wide 

 as the oesophagus at the point encircled. The short tail is conical to the 

 blunt terminus and is traversed transversely by distinct anal muscles. To 

 the indistinct vulva succeeds a vagina Supplied with a chitinous lining 

 and the usual glands. The reflexed portions of the ovaries are narrow and 

 filled with double rows of developing ova, and extend as far back as the 

 vulva. The eggs are one-half as wide as the body and two to three times 

 as long as wide, and are deposited before segmentation begins. The male 

 is unknown. 

 Hab. Roots and stems of grass, Sydney, Australia, at all seasons. 



