NO. II TWO NEW NEMATODES CHITWOOD 3 



surrounded by two indistinctly trilobed pseudolabia. Cephalic papillae 

 consisting of completely fused dorsodorsal-laterodorsal and ventro- 

 ventral-lateroventral ; remaining papillae rudimentary. 



Male 5.5 mm long by 85 fi wide. Stoma 60 jx long. Esophagus 890 /* 

 long, consisting of a narrow anterior muscular part 200 p. long by 18 jn 

 wide and a wide posterior glandular part 690 fx long by 40 fx. wide. 

 Nerve ring 140 ix from anterior extremity. Cloacal opening 155 /x 

 from posterior extremity. Genital papillae consisting of four pairs 

 of preanal and five pairs of postanal papillae. Left spicule 260 /* 

 long, setiform, apparently alate. Right spicule 65 fx long, thick, 

 hooklike. Caudal alae vesicular. 



Female 11 to 12.3 mm long by 100 to 120 p. wide. Stoma 55 to 58 i*. 

 long. Esophagus i.i to 1.12 mm long, consisting of an anterior part 

 215 to 270 /x long by 19 [x wide and a posterior part 850 to 885 /x long 

 by 47 to 60 IX wide. Nerve ring 157 to 180 p from anterior extremity ; 

 excretory pore 190 to 220 p from anterior extremity. Anus 119 to 

 150 /x from posterior extremity; tail slightly attenuated, distally blunt. 

 Vulva preequatorial, 4.8 mm from anterior extremity in specimen 

 12.3 mm long. Vagina directed anteriad, 125 p long; uteri divergent. 

 Eggs 38 /x long by 32 /x wide. 



Host. — Coelorhynchus sp. (J-S 650). 



L ocation. — Intestine. 



Locality. — Station loi (lat. i8°40'3o" N., long. 64°5o' W.). 



Type specimens. — U.S.N.M. Helm. Coll. no. 8153; paratypes no. 



8754. 



At the present time there seems to be no satisfactory means of 

 separating the genera Ascarophis and Spinitectus. The presence of 

 spines, which has generally been regarded as characteristic of the 

 genus Spinitectus, can no longer be considered sufficient. Baylis 

 (1929) described a species, S. giintheri, without spines, which he 

 placed in that genus, and this view cannot be criticized, for Mueller 

 and Van Cleave (1932) have shown that spines in these forms are 

 merely modified edges of posteriorly projecting annules. The pres- 

 ence or absence of spines is apparently not correlated with other 

 characters such as the stoma, vagina, origin of uteri, or number of 

 genital papillae. 



Ascarophis cestus is similar to A. acipenserina (syn. Cyclozone 

 acipenserina Dogiel, 1932) in having a cuticular " collar," a character 

 upon which the genus Cyclosone was based. Dogiel considered the 

 collar as a homolog of cordons characteristic of the Acuariinae. As 

 may easily be seen from the accompanying illustration (pi. i, fig. 8), 



