264 REPORT OF COMMISSIONER OF FISH AND FISHERIES.  [558} 
the second pair very narrow and elongated, subcylindrical, slightly 
flattened on the inner side, the palmary margin longitudinal, and scarcely 
distinct from the posterior margin. Fourth segment of the abdomen 
with a median fascicle of two large and two small spines, but no lateral 
fascicles. Fifth and sixth segments with both median and lateral 
fascicles of spines. 
Color in life grayish white, the posterior margins of the segments 
bordered with brown, giving the body an annulated appearance. 
Length, 12-18™. 
New Haven, Connecticut, and Eastport, Maine, and doubtless abundant 
at other points on the coast. 
This species closely resembles the fresh-water G. fasciatus, but is 
distinguished from it by the proportions of the segments of the pedun- 
cles of the antenne, and by wanting the lateral fascicles of spines upon 
the fourth segment of the abdomen. 
GAMMARUS NATATOR Smith, sp. nov. (p. 439.) 
Male: Eyes large, enlongated, but only slightly reniform. Anten- 
nula short and stout, about three-sevenths as long as the body; flagellum 
but little longer than the peduncle; secondary flagellum nearly half as. 
long as the primary. Antenna considerably longer than the antennula ; 
penultimate segment of the peduncle reaching to the extremity of the 
peduncle of the antennula; ultimate segment of the peduncle longer 
than the penultimate; flagellum about two-thirds as long as the pedun- 
cle. Both antennule and antenne are furnished with very long hairs, 
of which many on the antennule are plumose. First, second, and third 
epimera margined on the inferior edges with long cilia. First pair of 
legs more slender than the second; propodus ovai, twice as long as. 
broad, palmary margin continuous with the inferior, with a very narrow 
lamellar edge, a stout obtuse spine in the middle, and two smaller ones. 
at the inferior angle; dactylus strongly curved. ‘In the second pair the 
propodus is more than half as broad as long, and somewhat rectangular 
in outline, except that the palmary margin is slightly oblique; the pal- 
mary margin has a narrow lamellar edge, with a slight emargination in 
the middle, from which a stout obtuse spine arises, and at the inferior 
angle there are two or three smaller spines, as in the first pair. The 
inferior edges of the carpi and propodi of both pairs of legs are thickly 
clothed with long hairs. Natatory flegs reaching to the tips of the 
telson. Second and third segments of the abdomen with the sides. 
produced backward, and the postero-inferior angle acute. Fourth 
segment with only a median fascicle of spines; fifth and sixth 
segments with median and lateral fascicles. Rami of the posterior 
caudal stylets lanceolate, five or six times as long as broad, the outer 
extending beyond the inner by thejlength of its terminal article, which 
is very slender, almost spiniform, the edges of both rami clothed with 
long plumose hairs. Hach division of the telson nearly three times as. 
long as broad. 
