266 
REPORT—1868. 
Arter (Videnskabs Selsk. Forhandl. for 1863), p.2. Some young Thysa- 
nopode were taken in the surface-net at the Out Skerries in 1861; but 
only one specimen is sufficiently developed to enable me to feel confident 
that it has acquired the characters of the adult, and that one being a 
male, which is not separately described by Sars, I feel some doubt as to 
the identification, more especially as the young females differ in some 
respects (which may be the result of age) from Sars’s description. 
Mysis flewuosa (Miller)= Mysis chameleon, Bell, Brit. Crust. p. 336. Com- 
mon in rock-pools. 
—— inermis, Rathke, Beitr. zur Fauna Norw. Nov. Act. Ces.-Leop. xx. 
p. 20; Lilljeborg, Ofvers. af Vet. Akad. Foérhandl. 1852, p. 3; Frey u. 
Leuckart, Beitriige zur Kenntniss, Wirbellos. Thiere, p. 160 ; G. O. Sars, 
Beretning (1863) Zool. Reise i Christiania (1864), p. 16, = Mysis 
cornuta, Naturhistorisk Tidsskrift, Tredie Reekke, vol. i. (1861) p. 26, 
pl. i. fig. 3, a-y ; Goes, Crust. Decap. Podoph. Sueciz, p. 14. 
Antennal scale oblong, 4-5 times as long as broad, not half as long 
again as peduncle of upper antenns, about twice as long as the eye; 
apex very obliquely truncate, a spine at the external angle; outer mar- 
gin smooth. Rostrum distinctly produced into a triangular spine of 
moderate length. Eye-stalks ornamented with dendritic pigment mark- 
ings. Pereiopods with the propodos 4-articulate; nail well formed. Tel- 
son closely resembling that of M. fleauosa, the cleft slightly deeper and 
narrower ; 16-18 spines on each side, greatest distance between the last 
and penultimate spine. Fourth abdominal foot in male less slender and 
more evenly rounded throughout its length than that of M. flewuosa, to 
which, in its general character, it closely approaches ; antepenultimate 
joint not having any angular projection at its extremity ; its seta fully 
half as long as penultimate joint, which does not exceed the last joint 
in length. 
Distinguished from MW. flexuosa chiefly by its large and acuter ros- 
trum, and its shorter antennal scale. Rock-pools, Shetland, scarce ; 
also Cullercoats, Northumberland (A. M. N.), and Banff (Mr. Edward). 
—— spiritus, Norman, Ann. Nat. Hist. Dec. 1860, pl. viii. fig. 1; Trans. 
Tyneside Nat. Field Club, vol. iv. p. 329, pl. xvii. fig. 1; G. O. Sars, 
Beretning (1865) Zoologisk Reise ved Kysterne af Christianias og Chris- 
iia Stifter, 1866, p. 19. 5-8 miles off Balta, 40-50 fathoms, 
1867. 
The following are important characteristics of this species, to distin- 
guish it from the next :—Antennal scale not widening from base to the 
spine on external margin, that spine (in both sexes) at about three- 
fifths of the distance from the base to the extremity. Eyes on long 
stalks, which project beyond sides of carapace. Inner margin of inner 
uropods with a dense crowded row of unequal-sized spines, so closely 
packed as to touch each other at their bases. Male having the sexual 
lobe of superior antenne much shorter than the peduncle; the fourth 
foot of pleon with the first three joints subequal in length, and the last 
joint subequal to the fourth. 
ornata, G. O. Sars, Beretning (1863) Zoologisk Reise i Christiania- 
stift. 1864, p. 18. 
tyes short, scarcely reaching beyond the sides of the carapace, and 
thick, widening at the cornea, which is somewhat kidney-shaped. Su- 
perior antenne with a stout peduncle, which is shorter than the pedun- 
cle of the inferior antenne ; flagella longer than the pereion. Inferior 
