BY N. A. COBB. 405 



considerable number of hairs, especially ventrally submedian ones, 

 is conoid to the slightly expanded three-haired terminus, where 

 the very sticky secretion of the caudal glands finds exit. 



1- 10- 23- — M 84- _, - , . , , 



^ — 2^0 — gTg — ^ — 2^ 1-6 mm. Jixccpt tor being some what shorter 



and arcuate, and possessing a rather prominent anus, the tail of 

 the male is precisely like that of the female. The two equal 

 linear spicula are of uniform size, being curved in the middle and 

 having a length one and a half times as great as the anal body- 

 diameter ; their proximse are cephalated by expansion. The 

 accessory pieces are one-half as long as the spicula and have their 

 proximal ends expanded. Two long submedian hairs occur oppo- 

 site each other just in front of the anus. 



Hab. — This Nematode is not uncommon in marine sand and 

 mud. Port Jackson, New South Wales, Australia, 1893. 



1 7V/r -8 6-7 17- -57-^Q 81- 

 4. M. SETOSISSIMA, n.sp. 1-9 3.4 3:9 ^ 2^ 1-41 mm. ThlS 



remarkable form presents simple transverse striae, resolvable 

 with moderate powers. Throughout the length of the body the 

 cuticle bears numerous slender hairs, whose length is about equal 

 to three-fourths the width of the body. The cephalic setae are 

 particularly numerous, the larger ones being much stouter and 

 longer even than those found on the body. The cephalic row of 

 setae is situated near the anterior margin of the head, and must 

 not be confounded with the four pairs of subcephalic setae growing 

 close by ; these latter are only half as long as the largest of the 

 true cephalic hairs. The longest hairs in the true cephalic row 

 are. as usual, the submedian ones ; of these there are eight, all of 

 equal length, growing in pairs, one pair on each submedian line. 

 Next in size to these, and almost as long, are four sublateral 

 hairs ; these grow one on either side of each lateral line. Alter- 

 nating with these and with the submedian pairs are eight very 

 much shorter hairs. Thus it will be seen that the full complement 

 is twenty hairs. Add to these the four pairs of subcephalic setae, 

 and we have in all twenty -eight hairs. To what end, one naturally 

 asks, has this armature been developed? Most probably these 

 hairs are tactile and serve to guide the worm in its peregrinations 



