274 ORDER POLYLAIMIA 



nus, where the conoid spinneret has a diameter about one-fifth as great as that 

 of the base of the tail. From the slightly elevated vulva the vagina leads inward 

 half way across the body, where it joins the two, symmetrically placed uteri. 

 The ovaries reach about half way back to the vulva, at least in specimens in 

 which the uteri are empty. There are eight to ten ova in each ovary, arranged 

 single file. 



1.1 3-3 5-8 "-K 95-9 >, 6 



tj 1.3 M 1.4^1.4 The spinneret of the male is about one-third as 



wide as the base of the tail. No supplements or special setae or papillae have 

 been observed either in front of the anus or behind it. The spicula are rather 

 uniform and taper to an acute point in their distal thirds; in profile their proxi- 

 mal ends are seen to lie near the ventral surface of the body. The ejaculatory 

 duct is about half as wide as the body. 



Habitat: Mud, tide pool, Portsmouth, N. H., U. S. A. Sublimate to balsam. 

 Fig. 58, p. 273. 



1.5 6.3 . 10. "*41" 85. 



59. Polylaimium exile n. sp. > L ' 1,2 1.2 i. >lb " Striae of the thin 

 cuticle minute. It seems very likely that four cephalic setae have been lost 

 from the specimen from which the description and illustration are drawn. Lips 

 three, and double, (or possibly six), with six minute labial papillae. Cuticle 

 naked. Neck convex-conoid, especially toward the head. The oesophagus at 

 the nerve-ring is one-half, just in front of the cardiac swelling one-half, and 

 finally two-thirds, as wide as the corresponding portion of the neck. The elon- 

 Ib(6) aJ (6) gate( * to Pyrifp 1 cardiac bulb is very small. The lining of the 



""/56k oesophagus is quite distinct and at first is indicated by two refrac- 



ph ml . /^ tive lines, occupying a space one-sixth as wide as that of the 



, 1 1 k oesophagus. There appear to be no glands in its fine colorless 



ifr l musculature. There is an indistinct cardia. The thick-walled 



ejf |n .. fjj intestine is set off by a collum one-third as wide as the base of the 

 I I ] I Yf neck; it has a faint lumen and becomes at once two-thirds as 

 . 50 .M 1 w wide as the body. In cross-section it is made up of two to three 

 cells. Anus more or less continuous; rectum somewhat cutinized, equal in 

 length to the anal body-diameter. The granules contained in the intestinal 

 cells are numerous, uniform and colorless. The tail is conoid from the anus, 

 and then cylindroid in the posterior half, where it is two-thirds as wide as at the 

 base. It is probable that the caudal glands are small and located near the anus. 

 There are no caudal setae. Renette present; excretory pore probably located 

 near the nerve-ring. Full-grown ova are twice as long as the body is wide, 

 and nearly one-half as wide as long. The reflexed parts of the ovaries reach 

 about three to four body-widths back toward the vulva. 



Habitat: Sand below low-tide mark, Belmar, New Jersey, U. S. A. Sublimate 

 to balsam. Apparently the species is syngonic. Up to the present time 

 extremely few free-living marine nemas have been observed to be syngonic. 

 A similar species with four setae occurs at Woods Hole, Mass, U. S. A. Fig. 59. 



60. Myolaimus heterurus n. sp. Cuticle thin, naked; striae fine. Lips thin, 

 low, flat, confluent; six, or three and two-parted. Amphids faint, in the form 

 of transverse slits. That portion of the pharynx in front of the amphids is 

 about half as wide as the lip region; this chamber is continued by a narrower 

 tubular portion, nearly one-third as long as the neck and surrounded by a pecul- 

 iar radial musculature, differing from that of the oesophagus proper. Nearly as 

 far behind the amphids as these latter are behind the anterior extremity, there 

 is a prominent infolding in the wall of the pharynx. The amphids are difficult 



