FREE-LIVING NEMATODES 23 



slender oesophagus, bulb and intestine, a / eo 



more strictly conoid tail, and a somewhat .'-- -'-> i. r .a 



thinner cuticule, the striations of which are 



even less modified on the lateral fields. There are about four hundred and fifty 

 transverse striae. The cuticle is hardly perceptibly modified on the lateral fields 

 in the anterior half of the body, but in the posterior half, especially opposite the 

 copulatory muscles, there is a distinct modification, which at its widest part is 

 nearly twice as wide as one of the corresponding striae. The modification be- 

 comes less pronounced behind the anus, and disappears near the terminus. The 

 renette cell occurs at a distance behind the neck equal to twice the diameter of 

 the body. 



The stoutish, somewhat tapering, rather blunt, yellowish spicula are one and 

 one-fourth times as long as the anal body diameter, and at their widest point one- 

 sixth as wide as the body. They are almost imperceptibly cephalated by expan- 

 sion and lie with their proximae a little ventral to the body axis. The frame has 

 a median piece from near the middle onward. The two arcuate, slender, rather 

 strong accessory pieces are three-fifths as long as the spicula and lie parallel to 

 them. The seven chitinized supplementary organs, separated from each other 

 by a distance equal to the diameter of one of the organs, occupy a space about 

 equal to one and one-half times the body diameter, the posterior one occurring 

 about opposite the proximal ends of the spicula. These organs are very much like 

 those of Chromadora minor. The ejaculatory duct and vas deferens are one- 

 fourth, the broad cylindroid testis one-half as wide as the body. Copulatory 

 muscles extend forward somewhat beyond the supplementary organs. 



Habitat; remarks. Bay, Cape Royds. Two good specimens, both v male. 



SPILOPHORA, Bastian, 1865 



The following are characters common to all the species of Spilophora here 

 described. 



Cuticle with two lateral wings, beginning near the head and ending on the tail. 

 Neck conoid. Tail tapering from somewhat in front of the anus. The lips are 

 small and often indistinct, but when decipherable can usually be seen to be twelve 

 in number, each with a single forward-pointing papilla. Throughout most of its 

 length the oesophagus is more or less cylindroid, but ends posteriorly in a pyriform 

 bulb two-thirds to four-fifths as wide as the base of the neck, and containing a 

 fusiform valve (sometimes obscure) one-fourth to one-half as wide as itself. There 

 is no distinct cardia. The intestine is separated from the oesophagus by a distinct 

 broad constriction about one-third as wide as the corresponding part of the body. 

 The more or less prominent chitinized rectum, about as long as the anal body diam- 

 eter, leads inward and forward. The caudal setae are small and scattered. The 

 nerve-ring is of medium size and surrounds the oesophagus rather squarely, and is 

 accompanied by distinct nerve cells. The vulva is more or less elevated and con- 

 spicuous and from it the vagina leads inward at right angles to the ventral surface 

 about half way across the body. So far as known the eggs are ellipsoidal. The 

 rather slender, blunt spicula are about one and one-fourth times as long as the 

 anal body diameter. The arcuate accessory piece is parallel to, and half to 

 three-fourths as long as, the spicula. The testis is relatively wide. 



