432 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



A single specinn-ii colk'C'ttil July 30, 1900, was at first thought to Vk' near />. ftrrmiiium. The 

 general habit of the body is much a.* in tiiat speciesf. The o|H'nln)Xof the acetabulum, however, instead 

 of iH'irip tnmsverse, is lonjrituilinal. It suKgests also Heniilen's /'. i-ixluidrs, but the testes appear to lie 

 transversely near the posterior end instead of on the meilian line. As farascan be made out from an 

 examination of the specimen in glycerine, it has the followin); characters: Body smooth, thii-kish. 

 depressed, of nearly the same breadth Ihroujrhout, rounded at each extremity; a|)ertureof mouth nearly 

 cir<-ular, a little wider than lonj;; acetabulum much larjrer than oral sucker, aperture elongated; 

 pharynx pyriform, with the larger end in front and overlappfnl by the oral sucker; lesophagus at least 

 at- long a." pharynx; intestinal rami not clearly made out, but apparently simple and n-aehing to the 

 I)Osterior end; cirrus passes dorsal to the acetabulum to the right of the lesophagusas farasthe pharynx, 

 whence it curves back and opens at the anterior border of the acetabulum. Testes two, side by side 

 near the posterior end; ovary smaller, apparently two-lobed, in front of te.stes and toward the left; uterus 

 in front of testes in middle of.lxxly; ova of different sizes. Vitellaria two narrow dusters of small <lark- 

 brown bodies lateral to the testes, the one on the right extending less than halfway to the acetabulum, 

 the othera little more than halfway. Dimensions in millimeters: I-ength, 7.5; l)readtli,2; oral sucker, 

 length 0.!l7, breadth O.SM, aperture 0."J."> long ami O.L'S wide; acetabulum, length 1.3S, breadth 1.5, 

 aperture 0.48 long and 0.33 wide; pharynx, length 0.44, greatest breadth 0.33; lander ova 0.086 and 

 0.045, smaller 0.0(52 and 0.035, in the two principal diameters. 



Tetronarce occidentalis, Torpedo. 



FOOD. 



The alimentary canal was nearly empty in all the torpedoes I have examined, a few remains of lish 

 lieing about the oidy idcntihable contents. The stomach and intestine in all cases, including one 

 specimen examined in IHSft and two in I!)IH). containeil an extremely viscid and tenacious mucus. 

 The extraorilinary thickness of the walls of the alimentary tract is ajiparently as.«ociated witii e<^ually 

 extraordinary digestive jKiwer. 



CKSTUltKS. 



1. ('iiliiplriiliolhriiiiii orrideiildlf Linton. Spiral valve. 7, |)p. 274-27") and 2il,S-299, pi. xi,[, tigs. 92-97. 



.July 29, 1S99; 3 strf.biles; .scolices not found. .July IH, 1900; 5. small, 20 to 27 mm. in length, 

 only 1 with scolex. The changes wrought in the appearance of thescolex of this species by 

 different states of contraction are very diverse. 



2. llhijncliobiAhriHm imptirixphie Linton. Larvre in cysts in intestinal wall. 7. p. 275. 



3. Tclrarlijinchus bimilcalKx \Anton. 5, pp. .SIO-SII, pi. i.xvi, tigs. 13, 14. 



Dasyatis centrura ( Tnjijoii riiilrnrn), Stitnj linij. 



Tlie stomachs of the sting rays which I have examined have l)een, a,-; a rule, empty. Fragments 

 of Crustacea and annelids, however, have been found in most ca.ses somewhere in the alimentary tract; 

 small (isli reconlcil in one instance. 



.\KM AldDK-i. 



1. .UmriK (.''). Immature, .'spiral valve. 



\ single specimen collected .\ugust I, l.ss7. It is iiijiualurc. has bi'i'ii iiitniducei with fond, anil 

 the sting ray may nfit be its i>ro]ier host. Body smooth, of nearly uniform diameter, with line 

 longitudinal stri;e. Heail with four blunt, rather obscure jjapillie. Tail slenderly mucronate. Some 

 dimensions in millimeters: lA?ngth, IS; diameter of head, 0.08; length of owiphagus 1.12, diameter 

 2 nun. from head at middle and 2 mm. from ])o.sterior end 0.22; diameter at anal aperture, 0.12; distance 

 of anal aperture from posterior end. 0. US. The body enlarges slightly at base of lesophagus. 



CK.STODES. ■ 



All excei't encyste<l forms from s[>iral valve. 



2. .[nIholKilhriitiii piilriiiiiluin Linton. [Rlioiloholliriiim piilrlmidiin, .Viii. Journ. Sci. and .\rls. .March, 



1889.] a, |)p. 7,5!l-7().5, i)l. iv, tigs. 4-9; pi. v, figs. 1-2. 5, pp. 4:{9-440, pi. x.vx, lig. 1. 7, 

 p. 275. -Vug. 24, 1899; 1; large, with large number of free proglottiiles. 



