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ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 267 
antenn having basal joint very short, triangular, the second long, the 
third two-thirds length of second ; flagellum long; antennal scale about 
one-third longer than the peduncle, widening from the base to the 
spine of external margin, thence narrower by a very oblique truncation 
to the apex; the very large spine in the middle of the external margin ; 
external margin below the spine naked, beyond the spine, apex, and 
inner margin with long plumose sete, the second joint of scale having 
one seta on each side and three terminal. Last joint of pereiopods 7-arti- 
culate. Sixth segment of pleon only slightly longer than fifth. Telson 
subequal in length to inner lamelle, and longer than preceding seg- 
ment; lateral spines 25-30; cleft moderately deep, and wide toward 
the extremity, the sides being only slightly convex, and the serration 
longer and larger than usual distally. Inner uropods furnished with 
long plumose sete all round, and a row of 16-19 rather long subequal 
spines, separated from each other on the inner margin. Outer lamelle 
narrow, and of nearly. equal breadth throughout, nearly half as long 
again as the inner. The male has the sexual lobe of the superior 
antenne unusually long, as long as the whole peduncle. The antennal 
scale is narrower than in the female, the spine nearer the apex than 
the base, and the breadth not greater at that point than nearer the 
base. The fourth foot of pleon is very long, and reaches beyond the 
telson; the outer branch very like that of WM. spiritus, but the third 
joint is much longer than either of the two first, which are subequal ; 
fifth joint not more than half the length of the fourth. Animal more 
or less tinted with yellowish or red. A specimen sent to me by Mr. 
Edward of Banff was of a very delicate rose-colour. 
Taken 5-8 miles east of Balta, in 40-50 fathoms ; and also off Sea- 
ham on the Durham coast (A. M. N.), Banff (Mr. Edward). 
Mysis vulgaris, J. VY. Thompson. In the stream which runs into Deal Voe, 
near Lerwick. 
Mysidopsis didelphys (Norman). Mysis didelphys, Tyneside Nat. Field Club, 
yol. v. p. 270, pl. xii. figs. 9-11; Mysidopsis didelphys, G. O. Sars, 
Beretning (1863) Zoologisk Reise i Christiania-stift. (1864) p.27. Rare, 
5-8 miles east of Balta, 40-50 fathoms. 
——? hispida, n.sp. Body hispid all over, the hispidity evident even on the 
peduncles of the eyes. Eye-stalks of moderate length. Carapace pro- 
duced into a broadly triangular rostrum of considerable length, reach- 
ing beyond the middle of the first joint of the superior antenne; a 
notch on each side of the front margin of carapace opposite the centre 
of the insertion of the eye. Superior antenne with peduncle twice as 
long as the eye-stalk ; first joint long, slender, very concave above, two 
following much thicker, the third double the length of the second, 
hispid like the body. Inferior antenne with peduncle only reaching 
the extremity of the penultimate joint of the superior; scale pro- 
duced, slenderly subulate, nearly twice as long as peduncle of superior 
antenne (somewhat less in ¢), two-jointed, second joint one-third 
total length, both margins fringed with long plumose set, the second 
joint having on each side four lateral at long intervals, and three 
terminal. Last joints of pereiopods 4-articulate, first articulation as 
long as the two following. Pleopods asin Mysis. Telson linguiform, 
long and narrow, subequal to preceding segment; sides margined with 
30-35 spines, which are of equal length at first, but towards the 
extremity much larger spines alternate at various distances (e. g. every 
v2 
