480 BULLETIN OK THE UNITED STATES FISH COMMISSIOX. 



attenuate anteriorly, the greatest diameter V)einj: not far from the posterior end. The postanal portion 

 is slender but more acute in the male than in the female. In the male the posterior end is recurved. 

 The body is cros.«ed by very fine transverse strije. The lips are without tooth plates. The upper lip 

 i.s somewhat elliptical, it.^ dimensions in the female beinp, length 0.2 mm., breadth at middle 0.10 mm., 

 breadth at base 0.1 mm. Si.x postanal papilhe were made out in the male, two pairs remote from llie 

 anus and one pair near. Twelve preanal papilUe were seen — that is, two groups of thn-e each — on each 

 side; the papill.e in the anterior group not .<o close together as those in the posterior group, wluch lies 

 a short distance in front of the anal aperture. 



Dimensions of the two specimens in millimeters, the mmilicrs for the male standing tirst: U'ngtli, 

 :iSand 5(); diameter of head 0.2 and 0.3, 2 mm. back of liead 0..") and 0.7, maxinnnn (near posterior emlj 

 O.liS and 1.4(i, 2 mm. from jiosterior end 0.68 and 0.9, at anal aperture 0.24 and 0.5; distance from anal 

 aperture to posterior end 0.2 and 1. 10; length of (esophagus, male 2.44; length of copulatory spines, 2.3. 



Macrourus bairdii, l!itir<r.i (imiu'llir. 



.VCASTUDCEI'H .\ l,A . 



1. Kchhiorhi/ncliiix 'irii,t I\iidol|>lii. 



U. S. National Museum collei'tion; i-ollected by the I'. S. Kisb Conunission, station Sil4. Uirgest 

 specimen in this lot measures 21 mm. in length; diameter near anterior end 1.1 nnu., near middle O.S 

 mm., near iiosterior end 0.() inin. In a male of this lot the numK-r an<l arrangement of testes, cement 

 glands, and vas deferens agreeil with the sj)ecimens from the llat-lish. See !l, p. 52.5, etc. 



NEM.\T01)liS. 



2. .lw</rissp. liiiiiialMri'. | I'l. viv, ligs. ITo-lTS.] 



U. S. National Mu.seimi colleclion, four lots, collciti'd by the l'. S. Fish Commission steamer 

 AHiiUriKui, .stations 894, 2201, and 2739. These are all immature and range in length from 15 mm. to 3.'{ 

 mm. In most of the spi'cimens the embryonic cuticle was still attacheil, but in the process of sloughing 

 off. There is considerable variation in the lips and in the appi'arance of the posterior end with tli<> 

 <legree of development. On this ac<'onnt it is exceedingly dillicult to characterize these immature 

 nematodes briefly. Dimensions of one in ndllinieters arc given: Ix-ngth, 32; diameter of head 0.17, 

 near lii:id 0.25, nddille O.ti, near ])osterior end 0.33, at anal aperture 0.25, 5 nun. back of head 0.05, 5 

 mm. from posterior end 0.55; length of (csojdiagus, 3.3; di.stance from anal aperture to posterior end. 

 0.45. In a siiecimen mea.suring 33 nun. in length the greatest diameter was about 10 nun. from the 

 posterior end. The IxHly is smooth except for exceedingly minute transverse lines; lateral jaws with 

 about three teeth; upper li]! without papilhe, at lea.-t none wi're made out; length and breailth of lips 

 nearly equal. The interli]> in most is very short. 



3. I'liilili niiinnl in'innluilf. Stomach. [I'l. .\ix, figs. 224-227.] 



\ nematode whii-b re.send)Ies some of the free forms like JCiioplnx was found in the U.S. National 

 Mu.-<eimi collection from tlu; stomach of this host, U. S. Fish Commission station 8VI4. This is one of 

 the <lredging stations established by the steamer Fixh JIuiik, Octol)er 2, ISSO; depth, .'!()5 fathoms. 

 The specimens are slender-fu.'^iform, with a tendency to a.-smne an annate i>osition. Four pairs of 

 small, gently curving spines were counted around the mouth of one of the s|)ecimens, and a few othei-s 

 a short distance back of the head. The anterior end was retracted in »ne so that the siiecimen bore 

 some re.send>lance sui)erlicially to Ecliiiiin-hiinrJnut; posterior end acmiiinate. Body wall rather thick 

 and dense, with a few <lelicalc longitudinal liViei-s and exceedingly minute and crowded transverse libers. 

 The ie.so|)hagus is long and slender. About midway of its length a muscular sheath of coarse 

 longitudinal libers begins, which incloses its basal jiortion, and. continuing, envelops the intestine and 

 reiiroductive organs. .^ reproductive opening was noticed in one sjiecimen a little in front of the 

 ndddle in the wall of the muscular sheath. ■ The aperture in the outside wall did not quite coincide 

 with it, but had ])robably been displaced by the distortion of the specimen under the cover glass. 

 Dimensions in millimeters: Length, 12.5; diameter, anterior 0.12, middle 0.4, at anal aperture 0.13; 

 distance of anal aperture from jiosterior end, 0.22; length of o'.-iophagus, 1..54; ilistance .if repmductive 

 ai>erture from head. 5.5; transvei-se diameter of re[>roductivi- aperture 0.024, axial diameter O.OIS. 

 The ri-productive aperture was surrounded by a sphincter (1.01 mm. thick. 



ctsroDRs. 



4. RhynvholxAhriuin. Cysts. 'I, ji. 796, pi. i,xiii, tigs. 7, 8. 



