430 BULLETIN fiF THE UNITED STATES FISH COMMISSION. 



The resciuhlamv nl head to that of Mimnriigmn ihhnii'iliisrliirlii I/'pniilK'rj; in very striking. The 

 neck is iiiiniitcly serrate in nntline. The ri|)e sejiments are very easily cletarlitil. Some free segment.a 

 whii-h proliahly lielonfieil to tliis species were nnuli larger tlian the cliniensions of tlie last sejinient 

 >:iven l)elo\v. Dimensions of one in millimeters: I^njrth, :^.77; letifftli of heaii, O.oo; lireadlh of head, 

 0.-I2; iliameter of neck, 0. IS; liistance to first s^nient. l.ii; last segment, length, O.lio; breadth, 0.17. 

 ."Similar forms found in (iuleorerrlo and Ixunii'. 



4. Thi/.tunoceplKilum rirlipulum sp. nov. Spiral valve. [PI. xxvii, ligs. 294, 29.5.] 



A few very small specimens with scolices which a};ree in minute detail with the head proper of 

 7'. rrinpiiiii, hut without the characteristic psendoscolex of that species, were found. The hea<l is 

 i|uailraii;.'ular. the botliria oblong, each of the four witli two short, conical hooks, which are the lateral 

 l)rolongations of a transverse jiartition. The structure of these hooks is entirely different from that of 

 the onlinary chitinous hooks of cestodes and acanthocephala. It appears to lie of the same e.>'sential 

 nature a-s the thickened borders of the Ixjtliria, but ilen.ser. This Im." alreaily lieen shown for T. cnV- 

 linm (Report of U. S. Fish Commission for 18S8, p. 547, pi. i,.vii, tig. IS). Back of the hooks the 

 botliria are somewhat trough-shaped. In front of the hooks the bothria are i)rolonged in some, short 

 in others. The contraction states are more variable in the anterior than in the posterior i)art.s of the 

 botliria. The anterior portion evidently has suctorial functions. It has the appearance of a ilistinct 

 loculus in contraction. The strobiles are short, the proglottides rather irregular, easily detached, 

 posterior ones elliptical, making the chain nioniliform in outline, ninicnsions in millimeters: Ix-ngtli, 

 W.'.Mi; diameter of heail at hooks, 0.72; in another, 0.2<); length of bothrimn. 0.7.'); in another, 0.44; 

 breadth of bothrium, 0.50; in another, 0.17; length of hooks, O.Oti; diameter of neck 0.25, swelling 

 to 0.46 at 0.29 from head; ui another, 0.14, swelling to 0.20 at 0.14 from head. 



5. Plati/lmtlirliim pnrvuiii sp. nov. Spiral valve. 



The.^e specimens, of which 57 were found, are identical with Xo. (> under ('iirrlinrhiits mllhertl. 

 Upon superficial examination one would be disposed to place them in the genus I'lidreinholhriiim. The 

 character of the hooks, however, is nnmistakalile. The longe.st s|ieciniens mea.sure alwut 10 nnn. 

 They are not in good condition ior measuring, being more or less coiled up. The segments drop off 

 very easily. A few retained, six in one case, give to the strobile a characteristic nioniliform appear- 

 ance. In such cases the segments may be a little longer than broad, as long as broad or broader than 

 long. For further details of this species, see uiuler ('. milliirli. Xo. (>. 



f>. Tiinirhjini'IiHx rolntxtU!! hinton. .Scolex. sjiiral valve. One scolex with W-ginning of strobile. [I'l. 

 X.M, tig. 242.] 



Squalus acanthias, llnriinl Doij-Jixli, Sjiiiii/ llny-ji.sli. 



\ specimen examined by me .Inly 26, 1!H)0, had lieen confined in the pool two or three weeks. 

 The alimentary tract was almost entirely empty, except a few bit.s of eelgra.-^s ami the test of a young 

 sea-urchin 1.5 mm. in iliameter. Vinal N. ICd wards says he has examine<l the stomachs of this dog-fish 

 and found them (illed with ctenophores. No eiitozoa were found. Mr. C. V. Silvester reports tliat 

 he finds lish of various kinds in the stomachs of .spiny dog-tish from Provincetown, Ma.ss. 



7. ].. 274. 



Raja erinacea, Summfr Skate. 



Usually crusta<'ea and annelids, but bivalve mollusk.s, sipiid, and fish also frefiuently fonnd in the 

 stomacl). In the summer of 1899 thirty-two skates were examined and the following food material 

 noted: t'rabs (hermit, Ctnicer, C'aUinectcs, I'anitpfun, and others), shrimps, amphipods, annelids, squid, 

 bivalve moUusks, small (ish. 



XE.M.\TOI>KS. 



1. Ascaris rotumlnin Rudolphi. Stoniadi and intestine. [PI. ui, figs. 14-18.] 



Nematodes found on several occasions are referred to this species. Length of males, 12 to 18 mm. ; 

 females, 25 to 40 mm. There are three postanal, one large and two small, and eight or nine preanal 

 papilla; on each side in the male. Mouth trilobed, the lips projecting into blunt papilla, and 



