266 ORDER ISOLAIMIA 



Habitat: Ocean beach-sand, vicinity of Los Angeles, Calif., U. S. A., near loi 

 tide mark. Fig. 50, p. 265. 



1. 6. 14. 18-" 66. 



51. Halanonchus macrurus n. sp. * *- i-9 2.1 i. 

 cuticle is very finely and somewhat irregularly reticulated upon the head. Outer 

 row of cephalic setae stout, two-jointed. Lips probably distinct and six in num- 

 ber, thin, flap-like. Pharynx somewhat deeper than the base of the head is wide. 

 The pharynx has a faint triquetrous framework, the three, slender, longitudinal 

 elements of which are split behind (and also less conspicuously in front), the 



.,*,. <_;, tfttfi) branches thus made bowing round together; this imparts 



W to the wall of the pharynx, opposite the beginning of the 

 P sterior f ourt h> a junction-like effect. As a whole the 

 pharynx is much like an elongated and naked and weakened 

 Oncholaimus pharynx destitute of onchia. The cylindroid 

 to conoid oesophagus near the nerve-ring is three-fifths, 

 and finally two-thirds, as wide as the neck. The distinct 

 re f rac tive lining appears to be composed of two to three 

 faint elements, occupying a space three-fifths as wide as 

 the oesophagus; the musculature is coarse. Probably 

 glands are present in the oesophageal tissues. There is a 

 X 750 mor e or less hemispherical cardia, one-third as wide as the 

 neck. The thick-walled intestine is set off by a constriction one-third as wide 

 as the base of the neck, and becomes at once two-thirds as wide as the body. In 

 cross-section it is composed of about twelve cells. The rather inconspicuous 

 rectum is as long as the anal body-diameter. The cells of the intestine contain 

 scattered, colorless granules, of variable size, the largest of which are one-twen- 

 tieth as wide as the body. The larger granules darken in Flemming's solution. 

 The tail is first conoid, and then cylindroid in the posterior two-thirds, where 

 it is one-third as wide as at the base. It tapers from in front of the anus to the 

 terminus, which is apparently devoid of spinneret. The lateral fields are three- 

 fifths as wide as the body; their margins are rather distinctly indicated by the 

 abrupt beginning of the longitudinal musculature. Renette unknown. Nerve- 

 ring accompanied by obscure nerve cells. From the large, conspicuous, some- 

 what elevated vulva the large, tubular to conoid, non-cutinized vagina extends 

 obliquely backward a distance equal to the body-diameter. The uterus is twice 

 as long as the body is wide, and contains four to seven eggs, which are probably 

 deposited after segmentation begins. The narrow ovary tapers but little, and 

 contains about thirty ova arranged single file. The sub-arcuate, rather simple, 

 frail, blunt spicula are one-eighth as wide as the body; viewed in profile their 

 non-cephalated proximal ends appear to lie dorsad from the body-axis. The 

 single, more or less straight, very slender, frail, simple, parallel accessory piece 

 is one-third as long as the spicula. The fifteen to eighteen very inconspicuous, 

 sub-equidistant, papilloid, ventral supplementary organs occupy a space in front 

 of the anus seven times as long as the body-diameter; the posterior one lies 

 opposite the middle of the spicula. The distance between these organs is about 

 one-fourth of one body-diameter. For each supplement there is a "pore" in 

 the cuticle, and to this comes a "nerve-ending" that appears to project more or 

 less. The sperm cells are long and cylindroid. 



Habitat: Sand inside government cut, Biscayne Bay, Florida, U. S. A. Flem- 

 ming to glycerine jelly. Fig. 51. 



