ON THE SHETLAND CRUSTACEA, TUNICATA, ETC. 273 
The genus Cyrianassa is founded on the male of Jphinoé. The genus 
is characterized (chiefly) by having the pereion very long, five segments 
uncovered by carapace, and its posterior segments scarcely deeper than 
those of pleon ; the last four pereiopods in both sexes without a palp ; 
the telson rudimentary ; the uropods with both branches biarticulate, 
the inner strongly spined: and in the male by having the first five seg- 
ments of pleon furnished with well-developed biramous pleopods. I am 
by no means certain that the present species is not the male of IJphinoé 
trispinosa. Undoubted males of that species resemble the J. gracilis 
very closely, except that they have 2-3 spines on carapace, and the 
pleopods have not the long plumose sete which adorn those of the latter 
species. It is possible, however, that the development of these sete 
may depend upon age, and that the presence or absence of the small 
darsal spines may not constitute more than varietal distinction. Future 
observation must be left to clear up this point. 
Cuma scorpioides, Bate, Ann. Nat. Hist. 2nd ser. vol. xvii. (1856) p. 456, 
pl. xiv. fig. 2, =? Cancer scorpioides, Montagu, Linn. Trans. vol. ix. 
Taken in Balta Sound in 1863. Known by its strong angular and 
keeled carapace. Only four segments of pereion are exposed, and the 
penultimate and the antepenultimate of these are raised into a rounded 
rib across the back. The uropods have both branches two-jointed, and 
only half as long as peduncle, subequal to each other, inner with nume- 
rous short blunt spines, but the two distal ones of each joint long, outer 
with plumose sete on the inner margin; peduncle without spines or 
setee, but minutely serrulate on inner margin. The male, as in [phinoé, 
has five well-deyeloped pairs of pleopods. 
Order AMPHIPODA. 
Talitrus locusta (Linn.). 
Orchestia littorea (Montagu). 
Probolium monoculoides (Montagu)=Montagua monoculoides, Bate & West- 
wood. Bressay Sound, and 5-8 miles off Balta, 50 fathoms. Costa’s 
genus Probolium (Ricerche sui Crostacei Amfipodi del regno di Napoli, 
1853, p. 199) is synonymous with, and has precedence of, Bate’s Mon- 
tagua, which was established in 1855. 
—— marinum (Bate)= Montagua marina, Bate & Westwood. 5-8 miles 
east of Balta,.50 fathoms, and on the Skerries Outer Haaf, in 70-80 
fathoms. 
— Alderi (Bate) = Montagua Alderi, B. & W. A single specimen of 
what I consider a variety of this species taken in Lerwick Bay. It dif- 
fers from the ordinary form in having the hand of the second gnatho- 
pods longer, being more than twice as long as broad, and in the palm 
being less oblique, crenately toothed throughout (instead of in part 
only), and the projecting tooth-like process bounding the palm of smaller 
size. 
—— serratipes, n.sp. Antenne rather short. Second gnathopods with the 
metacarpus posteally produced into a small tooth-lhke process; wrist 
produced below into an elongated lobe, which stretches along the pos- 
terior margin of the hand (atter the manner of the genus Monoculodes) to 
half its length, and terminates in two or three sete; hand of large 
size, elongated, of somewhat unusual form, widest in the middle, from 
which point the posterior margin gently slopes towards the anterior 
