NO. 1123. 



PBOCEEDINdS OF THE NATIONAL MUSEUM. 



811 



The specimen from the torpedo was found iu the pyloric division of 

 the stomach; only the scolex present. It presents some differences 

 from typical scoleces of T. hisulcattim, the proboscides being stouter 

 than usual for that species. The proboscides were retracted and only 

 the short hooks at base of proboscis were seen at first; their length 

 was 0.014 mm. The specimen was then made transparent with oil of 

 cloves and the hooks found to agree in size and shajie with those of 

 T. hisulcatnm (figs. 13, 14) (Xo. 4834, U.S.N.M.). 



15. TETRARHYNCHUS ERINACEUS, Beneden. 



vl'late VII, ligs. 1-8.) 



Tetrarltynchiis erinaceiis. Beneden, Mem. Vers. Intest., pp. iJJS-lol, 3(i7, \>\. nviii; 

 Lfs Pois Belg., pi. v, fig. 12; pi. vi, fig. 3. — Ol.sson, Lund's Univ. Arsskrift, 

 III, p. 50, pi. II, figs. 42-44. 



A species which has hooks that bear a strong resemblance to those 

 of Rhyncliohotkrium imparuinne, Linton, but with a cystic habit much 

 like that of Synhothrinm, JilicoUe, occurs twice in my collection and once 

 in the United States National Museum collection : 



The first and last are encysted blastocysts of tlte type of >Si/n}>otliritim 



(fig-.l). 



Dimensions of speciinens fro}a lot No. 1 {alcoholic). — Length (^)f blasto- 

 cyst, 40 mm. ; length of anterior division, 2.5 : diameter of anterior divi- 

 sion, 2; average diameter of posterior division, 1.5; breadth of head 

 of embryo, 0.76; length of thick, strong hooks, 0.09; length of small, 

 slender hooks, 0.015; length of small hooks, 0.008. Color of i)osterior 

 division, opaque white; of anterior division, yellowish white. 



No. 3 consists of a single blastocyst, same type as No. 1. Dimen- 

 sions, alcoholic specimen: Length, 22 mm. ; length of anterior part of 

 blastocyst, 3; diameter of same, 2.5; diameter of posterior part, 1.5; 

 breadth of head, 0.72; diameter of neck, 0.5; length of large stout 

 hooks, 0.06 to 0.08; length of small hooks, 0.01 to 0.03; diameter of. 

 proboscis, exclusive of hooks, 0.1 ; length of embryo proper, 6 ; length 

 of contractile bulbs, 1.8. Posterior part of blastocyst, white; anterior, 

 brownish yellow. The hooks have the following arrangement: Two 

 longitudinal rows of large, stout, strongly recnrved hooks, flanked on 

 each side by two rows of smaller and slenderer hooks, also strongly 

 recurved; these again by two rows of slender hooks, those in the inner 

 row sharp-pointed, those in the outer row flat with truncate or notched 

 tips. These ten rows of large hooks cover a little more than half the 



