474 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [22] 
Several young specimens were obtained, measuring from 5 to 20™™ in 
length. In these the bothria were identical in shape and habit with 
those of the adult. In the younger specimens, however, the part of 
the head to which the bothria are attached was proportionally larger 
than it is in the adult. In the larger specimens of young the laciniate 
segments occurred throughout the entire length ; in smaller specimens 
they occurred only near the head and at the posterior end, while the 
intermediate parts of the strobile were unsegmented or marked with 
faint transverse lines. In many of the smallest forms there were no 
laciniate segments, while the posterior end of the strobile carried a num- 
ber of elongated segment-like bodies, totally unlike the segments of the 
adult. These pseudo-segments are evidently evanescent. (Plate IIT, 
Fig. 17.) 
Habitat.—Sand Shark ( Odontaspis littoralis), in spiral intestine, young 
and adult together, abundant, chyle swarming with free proglottides. 
July and August, Wood’s Holl, Mass. 
PHOREIOBOTHRIUM,* gen. nov. 
Near Cylindrophorus Diesing. 
Tetrabothrit Spec. Wagener. 
Cylindrophorus typicus Diesing, Revis. d. Ceph. Ab. Par., p. 264. 
Tetrabothrium Carcharie Rondolettii Wagener, Nov. Act. Nat. Cur., xxiv, 
Suppl. 4 and.84, tab. xxii, 270-273; Statu larve Wagener, 1. c. 4 and 84, 
tab. xxi, 266-268, tab. xxii, 269. . 
“Genus hoe insufficienter cognitum provisorio modo nomine Cylindrophori 
notavi” Diesing. 
Body elongated, articulate. Head separated from the body by a neck. 
Bothria four, opposite, tubular, parallel, entire, each armed with com- 
pound hooks and provided with one supplemental disk (auxiliary ace- 
tabulum) in front. Minute spines on neck, or on neck and body. Gen- 
ital apertures marginal. 
Phoreiobothrium lasium,t gen. et spec. nov. 
[Plate IV, Figs. 24-29. ] 
Head separated from the body by a neck. Bothria four, marginal, 
flat-tubular, subrectangular in outline, each with two compound hooks 
placed anteriorly, and one auxiliary acetabulum in front of hooks near 
the lateral edge of the bothrium. Face of the bothria hollowed out, 
with a thickened or raised border, so that each botkrium resembles a 
shallow tray. Inner edges of bothria united by a thin membrane, in 
which lie bands of fibrous tissue. Posterior end of the bothria ellip- 
tical, with a thickened ring or border, and marked with striz parallel 
with the smaller diameter. These striw, when highly magnified, prove 
to be low ridges, which give to the end of a bothrium the appearance 
of a coarse rasp. These strive or ridges are not seen plainly unless the 
* bopeiov = a tray. * Kéovog = bristly. 
