418 



TRICOMA AND OTHER NEW NEMATODE GENERA, 



f 



a bulb three-fourths as wide as the base of the neck. The cardiac 

 coUum is narrow and distinct. The thick-walled intestine is 

 three-fourths as wide as the body, and is composed of pigmented 

 cells of such a size that about ten build the circumference. The 

 intestine imi)arts a purple-madder colour to the 

 The lateral fields are about one- 

 third as wide as the body. 

 The ventral excretory pore 

 is situated just behind the 

 nerve-ring. The duct is 

 narrow, and the ampulla 

 rather indistinct ; I did 

 not discover the location 

 of the gland. The tail in 

 young specimens is conical 

 and arcuate, but in adults 

 is nearly hemispherical. I 

 saw no caudal glands. The 

 vulva is not conspicuous. 

 The uterus usually contains 

 a row of eight to ten thin- 

 shelled eggs, each about twice as long as the body 

 is wide, and less than half as wide as long. They 

 are evidently deposited before segmentation 

 begins. The spermatozoa are of such a size that four side by side 

 reach across the uterus. The eggs being white or translucent some- 

 times give the living worm a segmented appearance. The ovary 

 usually contains a row of sixteen to twenty developing ova, besides 

 the large number of very immature ova contained in the blind end. 



living worm. 



Fig. 12.— I, female Chro- 

 macjaster piirpxirea. II, III, 

 and IV, the head, neck, and 

 anal region of the same worm 

 more highlj' magnified. 



a, posterior end of oesopha- 



ffus. 

 h, cephalic setae. 



c, pharynx. 



d, lateral organ. 



e, beginning of oesophagus. 

 /, oesophagus. 



g, blind end of ovary. 



h, lateral organ. 



i, oesophagus. 



j, nerve-ring. 



k, excretory pore. 



I, unicellular gland (?). 



m, cardiac bulb. 



7i, cardiac constriction. 



0, proximal end left spiculum; 

 also points out the 

 vulva on the female. 



p, shaft of spiculum. 



q, accessory piece. 



1-3 2-8 ?- 



r68 



6-41 mm. The tail of the male is conical 

 and arcuate. There appear to be no caudal glands. There is no 

 bursa or other supplementary sexual organ. The two equal 

 slender spicula are uniformly arcuate, and are of nearly uniform 

 size throughout; they are twice as long as the anal body-diameter 

 and three-fourths as long as the tail. The accessory pieces are 

 somewhat L-shaped. 



