) 
122 Part III —Twenty-first Annual Report 
Genus Enhydrosoma, Boeck (1872). 
Enhydrosoma gracile, T. Scott, sp. n. Pl. ii, figs. 16-26 ; pl. ii, fig. 1. 
Description of the Female. — Body slender, cylindrical, slightly 
encurved, but otherwise similar to H. curvatum, Brady and Robertson 
(fig. 16). Length of specimen represented by the drawing about ‘45 mm. 
(=. of an inch). 
Antennules very short, moderately stout, and sparingly setiferous ; they 
are composed of four joints, the first three being sub-equal in length, but 
the last is considerably smaller than any of the others (fig. 17). The 
formula shows approximately the proportional lengths of the various 
joints :— 
AL TN ae ie Pts tO.) nee 
22 Lee OG nae er lan 
The antenne (fig. 18) appear to be somewhat like those of ZH. curvatum. 
The mandibles (fig. 19) are also similar to those of the same species. 
The second maxillipeds (fig. 20) have basal joint short, but the pre- 
ceding one is elongated, and the terminal claw is slender and moderately 
short. 
The first thoracic feet are somewhat like those of C. curvatum; the 
inner branches are short and two-jointed, the second joint being only 
slightly longer than the first, and their extremities, which do not reach to 
the end of the second joint of the outer branches, bear two elongated 
slender sete feathered ai the end ; the outer branches are three-jointed ; 
the first joint is fully as long as the entire length of the next two, but the 
end joint is shorter than the second one; each of the three joints is 
furnished with a moderately long and very slender seta on its outer aspect, 
while the end one also carries two elongated terminal sete similar to those 
on the inner branches (fig. 21). 
The second, third, and fourth pairs (figs. 22 and 23), which appear to 
differ little from each other, have the inner branches very short and com- 
posed of two joints, the first being very small, while the end joint is 
furnished with a few terminal setze as shown by the figures; the outer 
branches are three-jointed and of moderate length and stoutness, the 
middle joint is slightly shorter than the first or third. 
The fifth pair are broadly foliaceous, distinctly two-branched, and both 
branches are broadly sub-truncate at the end and provided with five mode- 
rately stout and elongated setze, the lengths of which vary to some extent 
as shown in the drawings ; a single seta springs from a small lobe near 
the outer distal angle of the outer branch (fig. 24). 
The furcal branches are very short (fig. 26). 
The ovisac is small and contains very few ova. 
The male appears to differ little from the female except in the structure 
of the antennules (pl. i1., fig. 1), and also to some extent in the form of 
the fifth feet. The fifth pair in the male consists of a rectangular plate 
about half as long as broad, and obscurely divided into two portions ; the 
inner portion is furnished with two moderately elongated sete on the 
lower edge, while the outer portion bears three or four setz as shown by 
the drawing (pl. 1., fig. 25). 
Habitat.—Shore at Musselburgh, Firth of Forth ; moderately rare. 
Remarks.—This species occurred with a number of other curious forms 
in a gathering collected in 1894. Several other new species were obtained 
in this gathering, but some of these have already been described.* This 
*See Thirteenth Annual Report of the Fishery Board for Scotland, Part III., p. 167, 
et seq.; Ann. and Mag. Nat. Hist. (6), vol. -xv., pp. 52-53; Ann. Scot. Nat. Hist., 
January, 1895. 
