PROCEEDINGS OF THE NATIONAL MUSEUM. 805 



ISTos. 11 and 13. From serous covering of viscera of remora. These 

 agree exactly with tyi)e. The cyst in ISTo. 11 was dark reddish brown, 

 translucent except at small end, wliich was almost black. Length, 36 

 mm. and greatest diameter 5; length of blastocyst 26, and greatest 

 diameter 1.5; very active and changeable. After lying overnight in 

 sea water, the blastocyst having become quiescent, the embryo was set 

 free. It was active and varied in length from 20 to 25 mm. Further 

 dimensions were: Length of liead and neck, 9 mm.; length of con- 

 tractile bulbs, 2.7; diameter of contractile bulbs, 0.32; length of pro- 

 boscides, approximate, 4.8; diameter of proboscides, 0.12. 



Proboscides very long, slender, and graceful, having tendency to coil 

 up; larger hooks on inner side of coil, smaller on outer side; arrange- 

 ment of hooks typical. 



Xo. L From common tiounder, on viscera, typical. Edges of bothria 

 often reflected and face of bothrium holloAved out. The posterior 

 emargination and median ridge are best seen in alcoholic specimens. 



11. RHYNCHOBOTHRIUM ATTENUATUM, Rudolphi. 



(Plate y, rtgs. 8-11.) 



lihynchobothrium iiHeuKntum, Diesing, Syst. Helm., I. p. 568; Revis. <1. ceph. Ab. 

 Parana., p. 307. 



No. 5459, U.S.ISr.M., parasites of swordtish {Xiphi((s (iJadius). 



1. Off Marthas Vineyard, Massachusetts, July 25, 1887', luimerous 

 specimens from peritoneum (No. 4761, U.S.N.M.). 



2. Three specimens collected by Professor W. Libbey, schooner 

 Grampus^ July 24, 1889. 



3. Sixteen specimens. No. 4715, T^.S.N.M., September 21. Trawl line 

 TJ. S. Fish Commission from outside stomach and intestine of swordtish. 



4. Twenty specimens, No. 4714, TT.S.N.M., from outside stomach of 

 swordtish. 



These worms agree with Diesing's descriptions of this species, and 

 resemble Leuckart's^ iigure of his Bothriocephalus elaviffevj which is 

 placed by Diesing under T. attenuatus, Rudolphi, in his Systema Hel- 

 minthum, but transferred to the genus Rhynchobotlirium in the 

 Eevision, with the following description: "Head ovate-conical, with 

 conical lateral bothria, bilocular by a longitudinal septum. Probos- 

 cides straight, clavate. Neck very long, decreasing behind, sometimes 

 transversely rugose, joints of the body papilliform.'' 



These larva? are grnb-like in appearance, the proboscides short and 

 thick, the hook -bearing portion being but little longer than broad. 

 Hooks of different shapes, but differing gradually from one ])art of pro- 

 boscis to another — better shown in sketch than in a written description. 

 The proboscides are in pairs at the apex of the bothria; the latter are 

 on the sides of the head, which corresi)ond with the flat surfaces of the 

 neck. 



1 Zool. Bruchst., I, pp. 51, 62, pi. ii, fig. 32. 



