302 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Fig. 10IJ is the sketch of a section through one of these small cysts; the longer diameter of the 

 blastocyst is 0.19 mm., the shorter 0.15. The blastocyst is surrounded by a tine granular coat, 0.007 

 mm. thick, with a few refractile bodies. This coat in turn is closely invested with a thin covering of 

 coimective tissue 0.003 mm. thick. Concentric layers of connective tissue arranged somewhat loosely 

 lie outside of this and are very abundantly supplied with nuclei. The latter layer is about O.OUS mm. 

 thick where the layers are most crowded, and 0.055 mm. where more open. Outside the concentric 

 nucleated area the connective tissue is normal, with few nuclei. These cysts lie in the subiuucosa. 



Ascaris clavata Kudolphi. 

 [Plato 43, figs. 105-108, U. S. N. M. No. 6532.] 



About 50 specimens were collected July 11 from the stomach of a pollock (PoUacltius rireus) by 

 Prof. U. M. Kelly. I have obtained this species frequently in former years from the cod and twice 

 from the pollock, although my notes on the species have never been published. Diesing's synopsis of 

 the species is : 



"Head with two linear posteriorly decurrent ahc ; mouth with large rounded lips. l!ody 

 anteriorly very much attenuated, moderately inflected; caudal extremity of the male iuHected with 

 uiucrouate tip ; copulatory spines arcuate." 



The following characters adapted from von Linstow's description are added, being in close 

 agreement with what I observe in these specimens : Head and tail ends inflected. Upper lip extended, 

 the pulp cylindrical, somewhat narrowed in the middle, two roundish projections on the inner side. 

 The anterior border and the base of the upper lip are of equal size and equal to half of the greatest 

 breadth. The two papilhe are small and situated far toward the front. The (esophagus measures 

 one-fourteenth of the body length. The intestine continues in front, where it springs from the 

 (esophagus into a c;ecum 1.8 mm. in length and lying beside the oesophagus, while the latter likewise 

 continues posteriorly in a ca-cum which lies beside the intestine and is of equal length with the first 

 ca-cuin, but only half as broad. The male is 45 inui. long (see below) and 1 mm. broad, the tail 

 measuring %*--; of the body length; the tail end is sharpened to a point, its extreme end being beset 

 with little brilliant elevations; the cirri measure 2.2 mm. and are thus relatively long. There 

 appear to be 27 preanal and 6 postanal papilhe. The female has a length of 70 and a breadth of 

 l.Ii mm. ; the tail is bluntly conical, with somewhat diminished tip; it equals ,{; of the body length. 



The foregoing description agrees well with the individuals under consideration, except that I 

 rind the length of my specimens falls short of the dimensions given by von Liustow. The largest 

 females measured GO and the largest males 40 mm. in length. 



In one specimen, a male, examined with some care, the (esophagus was about one-tenth of the 

 body length. The cephalad prolongation of the intestine at its juncture with the (esophagus was seen 

 distinctly; the caudad prolongation of the (esophagus was also made out, but less clearly. The 

 character of the cirri is exactly that given by von Linstow. The upper lip presents some differences 

 from the above description, the pulp being somewhat clavate in shape and relatively broader near 

 the anterior end than indicated in von Linstow's figure and description. The lip is also relatively 

 shorter and broader. The papilhe were not studied very closely in this lot, but so far as they could 

 be determined in a specimen seen in lateral view, they agreed in number and position with published 



descriptions of the species. 



Ascaris habena sp. nov. 



[Plato 43, figs. 109-115, U. S. N. M. No. G533.] 



On September 5, eight nematodes were obtained from stomach and intestines of two specimens 

 of toad-lish (Opsaniia t<in). 1 have seen this species often in previous years at AVoods Hole, in this host. 



Body tapering gracefully from near the posterior to the anterior end; jaws prominent, each with 

 lateral membranes and two papilhe, rhomboidal but rounded anteriorly, pulp expanding toward tip 

 and becoming broadly club-shaped and two-Iobed, each armed with four horny teeth. Tail somewhat 

 variable in preserved specimens, short conical or even truncate, sometimes mucronato at tip, that of 

 males shorter than females. Minute lateral wings are present at anterior end, though they were not 

 noticed until transverse sections were made. The cuticle generally is smooth, but transverse stria-, 

 0.01 mm. apart, were noticed near the posterior end in one case. The posterior end exhibits a strong 

 tendency to curve veutrally in the females as well as in the males. In fact, more success was had in 

 straightening the males than the females in the killing Uuid. The greatest diameter, especially in the 

 case of the females, is near the posterior end. 



