Cobb — Nematodes, mostly Australian and Fijian. 25 



organs are situated opposite the anterior part of the pharynx and are possessed of a 

 horny centre, being smaller in the females and more like clefts. The stoutly built 

 pharynx is supplied at the middle with an encircling ring ; in front of this ring it is 

 longitudinally striated. The dorsal tooth reaches beyond the ring, and there are one 

 or two others near the base of the pharynx. The median bulb is two-thirds as wide 

 as the neck, while the cardiac bulb is an elongated swelling, not bulbous. The brown 

 and somewhat tessellated intestine is marked off from the oesophagus by a distinct 

 constriction ; it is said to be composed of not above three rows of cells. The rectum 

 is three-fourths as long as the anal body-diameter. The ventral excretory pore 

 occurs at 9%, that is, considerably in front of the cardiac constriction. The finely- 

 pointed conoid tail is slightly concave somewhat behind the middle and bears a pair 

 of lateral papillae (pores ?). This species is viviparous, the uteri sometimes containing 

 a dozen embryos. The reflexed ovaries sometimes meet and cross. The proportions 

 of the male are precisely those of his mate, but he is somewhat smaller, usually 

 measuring only 2- mm. Papillae as follows : only one pre-anal submedian pair just in 

 front of the anus ; three lateral equidistant pairs on the anterior half of the tail 

 beginning near the anus ; two pairs submedian opposite the lateral three pairs ; two 

 pairs subventral close together opposite the anterior pairs of the preceding two 

 groups. The pores (?) found on the female occur also on the male. Spicula slender, 

 arcuate, one and one-half times as long as the anal body-diameter. Accessory pieces 

 one-half as long as the spicula, slipper-shaped, plump, and nearly surrounding the 

 tips of the spicula. Synonym, D. fictor, Bastian. 



Hab. — Found among fresh-water algae in Western Europe and England. Has 

 the habit of becoming suddenly still, as if dead. 



14. D. gracilis, Biitschli. 2-^ s'-e ^e- "s-i J" ' '^'^™- Neck convex-conoid; body wider 

 in the middle than at the vulva, namely 7"3 °/^; head rounded- truncate ; cephalic setae 

 six ; lips six, broad and flat ; pharynx cylindroid, composed of several horny pieces, 

 with possibly two rudimentary teeth at base ; both bulbs elongated, the median 

 central, the cardiac weaker ; oesophagus twice, the bulbs three times, as wide as the 

 pharynx ; intestine large, thin-walled, forming a shoulder in the cardiac region, 

 separated from the oesophagus by a deep constriction so that the coUum is only one- 

 fifth as wide ; cardia broad and distinct ; cardiac cavity two-thirds as wide as the 

 body and very long ; rectum half as long as the anal body-diameter ; tail concave- 

 conoid, diminishing in the anterior fifth to a width as great as the head, and thence 

 conical to the hair-fine terminus ; vulva inconspicuous, with almost invisible radial 

 muscles ; vagina one-third as long as the body is wide ; eggs same size as median 

 bulb ; ovary reaching at least three-fourths the way back to the vulva. The propor- 

 tions of the male agree fairly with those of the female, but the tail is shorter. Papillae 



