CRYSTALLONEMA, ZANEMA 



283 



cylindroid and one-fifth as wide as at the anus. There are no caudal setae. 

 The ellipsoidal to prolate renette cell lies close behind the neck, and is one-half 

 as long as the body is wide and five-sixths as wide as long. The large, continuous 

 vulva is inconspicuous. The medium-sized vagina extends two-fifths the way 

 across the body. There is a posterior rudimen- 

 tary branch to the sexual organs, three times as 

 long as the corresponding body diameter. The 

 uterus is four times as long as the body is wide, and 

 one-sixth to one-fifth as wide as long. The elon- 

 gated eggs are three times as long as the body is 

 wide. The relatively very small ovary contains 

 twelve ova, which diminish rapidly in size toward 

 the blind end, and are arranged single file. The 

 finely-granular, ripe ova are three times as long 

 as the body is wide, and three-fourths as wide as 

 long. 



Habitat: Sand, below Bathing Beach, Woods 

 Hole, Mass., U. S. A. Flemming to water. The 

 males of this species, C. fvscacephalum, are 

 unknown, but the males of two other species are 

 known to the writer. As these two are structu- 

 rally closely related to C. fuscacephalum, it may be 

 assumed that the spicula of C. fuscacephalum are 

 similar to those of these others, one of which is 

 Crystallonema simile n. sp., Miami, Fla., the anal 

 region of the male of which is shown in the adjac- 

 ent illustration, together with the dimensions of 

 both sexes. Besides being smaller, C. simile differs in lacking pigment at the 

 head end; in having relatively slightly longer and more nearly equal cephalic 

 setae; in having amphids relatively larger, three-sevenths as wide as the head; 

 in having the posterior oesophageal swelling almost indistinguishable; in having 

 the preliminary segment of the intestine as long as the body is wide, and the 

 intestine itself relatively a little wider, three-fourths as wide as the body. 

 Fig. 67a, p. 282, C. fuscacephalum; Fig. 676, C. simile, n. sp., type species. 



dnm 



X750 



..?:?... .*.?. 



1.2 1.3 



"-69 

 i.3 



-M" 

 "1.5" 



68. Zanema acanthurum n. 



Neck cylindroid. 



Cuticle naked. 

 It is possible that very small or broken 



(lui 

 I members of the submedian group of cephalic setae have 



//ph escaped notice, and that there are really three submedian 

 <-/4) setae on each lip. There appear to be six lips, but this 

 ' number is assumed largely on the basis of the six labial 

 ^P" appendages, shown in the illustration. The lips are rela- 

 amph tively rather thick, and are arched together over the 

 somewhat spheroidal pharynx. Oesophagus cylindroid. 

 The intestine becomes at once three-fourths as wide as 

 the body, and appears to be made up of cells of large 

 size, so that perhaps only two appear in the cross-section. 

 The posterior lip of the anus is slightly raised; rectum 

 about as long as the anal body diameter. The tail tapers from a little in front 

 of the anus and soon is reduced to a diameter about half as great as at the base. 

 Thence onward it tapers gently, so that near the terminus it has a diameter about 



seta// 



