STILBONEMA, LAXONEMA 



243 



narrow intestine, joined to a depression in the posterior surface of the cardiac 

 bulb, becomes at once about one-sixth as wide as the body, and then enlarges 



gradually until it is one-fourth as wide. Its 

 ^X 750 cross-section would show two cells. The lat- 

 eral fields are about one-fourth as wide as 

 the body, and contain' numerous nuclei. 

 Nerve-ring oblique. Tail conoid, arcuate. 



I. 3 ' * L 5 -M__ 98. 



1:2 a; lU" i:5--^iT6 3 - " Spicula slender. 

 "Acorn-shaped" accessory organs (see fig- 

 ure) far forward, so that the anterior one is 

 a little behind the neck. The cup-shaped 

 part of these organs has slightly different 

 refractive properties from the "acorn" itself, 

 which is plainly innervated. 



Habitat: Shoal in Kingston Harbor, 

 Jamaica, in one foot of water. Sublimate to balsam. Fig. 19a, p. 242; Fig. 196. 



20. Laxonema majum n. sp. - 6 .7 ^ .s' " Cephalic cuticle radi- 



ally striated; the basal part of the cephalic setae penetrate and interrupt the 

 cuticle. Inside the cephalic setae, as shown in the sketch, other interruptions 

 occur in the cuticle; possibly in some cases these are the "stumps" of lost setae. 

 There are two circlets of papillae inside the cephalic setae, one at a distance 

 from the mouth pore somewhat greater than the thickness of the body cuticle, 

 and the other twice as far away. Oesophagus nearly cylindroid, finally expand- 

 ing to form a pyriform cardiac bulb two-thirds as wide as the base of the neck. 

 There is no cardia. The intestine soon becomes about one-fifth as wide as the 

 body; at a distance back about twice as great as the body-diameter it expands 

 and becomes thicker-walled and one-third to one-half as wide as the body. Its 

 cross-section is composed of about four cells, each with ten to twenty brownish 



granules, the largest of pf/f . or ouph set^cph(4) 



which have a diameter ^S^'X ^st^^^fc^ j 



about one-fourth as great as \\ :\ *^,\\ Wm ^^ /] 



the thickness of the cuticle, """* \\^SM^^yifei^^A..^ . 



and the smaller one-third 

 to one-fourth -this size. , , 

 Renette unknown. The ^ 

 lateral fields are about one- 

 fourth as wide as the body, 

 and contain a double row of 

 nucleated cells, generally 

 somewhat rectangular in 

 form and separated into two 

 series. The nerve-ring is 

 probably a little behind the mai 

 middle of the oesophagus. 

 The tail of .the male is X 750 hmoe' setcdl spa 



arcuate-conoid and ends in a spinneret destitute of striations and having a 

 length about equal to the sum of the widths of the last eight striae. The tip of 

 the spinneret is somewhat differentiated, and its core presents minute longi- 

 tudinal "striations" which end just anterior to the terminal pore. The caudal 



