686 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



line vesicles. Length, in extension, about one inch; breadth, in middle, 

 0.10 to 0.12 of an inch. Head excentrically pedicellate upon a slender 

 neck, small, disk-like, rounded in front, or somewhat heart-shaped, with 

 the rounded point forward. Ocelli four, small, brownish, placed near the 

 attachment of the neck on each side ; those in the anterior pair farther 

 apart. Acetabulum large, well-rounded, as wide as the body, disk-shaped, 

 and attached nearly centrally. Male organ, when protruded, elongated, 

 conical, acute, placed just behind the fourth pair of large lateral white 

 spots. 



Color of back dusky brown or purplish brown, finely specked with 

 stellate points of darker brown, and with three irregular rows of con- 

 spicuous, small, round, opaque white spots along the upper surface of 

 the back. Sides with a row of about 16, larger and more conspicuous, 

 semicircuhir, white spots along the margin, each consisting of a cluster 

 of 3 to y small round spots, inclosing a more transparent area, in which 

 a diaphanous pulsating vesicle or enlarged vessel may be seen to pro- 

 trude at each pulsation. Lower surface of body light grayish, specked 

 with darker, and often with obscure transverse bands of whitish ; aceta- 

 bulum similar in color to the body, with small, round, white spots, the 

 margin more or less radiated with lighter and darker. Upper surface 

 of head similar to the back ; the sides and front lighter. 



West Kiver, near Xew Haven, on Fuwhdus pisculentus, November and 

 December, 1871 — F. S. Smith; Savin Rock, in salt-water, among eel- 

 grass — Prof. J. E. Todd; Casco Bay, among eel-grass, 1873— A. E. Ver- 

 rill. 



Tliis very active species lives in both fresh and salt water. 



The transparent lateral vesicles referred to are probably organs of 

 respiration, iuialogous to the much more highly developed branchial 

 appendages of Branchiohdella. 



ICHTHYOBDELLA EUNDULI Verrill. 

 Op. cit., vol. iii, p. 126, 187-2. 



Body smooth, distinctly annulated, subterete, thickest at about the 

 posterior third, tapering considerably toward the head, and slightly pos- 

 teriorly. Length about 0.75 of an inch ; greatest diameter about 0.08. 

 Head small, rounded in front, scarcely explanate, and separated only by 

 a slight constriction from the body. Ocelli four : two larger well sep- 

 arated, placed near the posterior part of the head ; two others, very 

 small and scarcely distinguishable in some specimens, are placed in 

 front of these. Acetabulum scarcely wider than the body, obliquely 

 attached, sessile, and scarcely separated by a constriction from the 

 body. Color light green, finely s^jiecked with dark green and brown 

 points ; sometimes with distinct bands of whitish alternating with tlis 

 green o/i the anterior part of the body, and with a pale dorsal line ; 

 neck with a pale band at the constriction. 



West Kiver, Conn., on Fundulus pisculentus, November and December, 



