50 
Gen. Pseudomysis, G. 0. Sars, 1880. n. 
Crastacea et Pycnogonida nova etc. 
Slsegtscharacteristik. Legemet af undersaetsig Form. 
Ilygskjoldet stort og bredt, fortil i Midten fremspringende. 
0inene ganske rudimentsere, uden Pigment eller Synsele- 
menter. Iste Par Felere af SEedvanligt Udseende. 2detPar 
Foleres Blad lancetformigt, rundt om bprstebesat. Mund- 
delene temmelig lig samme hos Slmgten Mysideis. Fqdderne 
forholdsvis smaa og svage, med mangeleddet Tarse og Ende- 
kloen ufuldkomment udviklet; Svpmmegrenene overordentlig 
forlsengede. Det midterste Halevedlneng sardeles kort, 
pladeformigt, bagtil indskaaret. De ydre Halevedhmng med 
vel udriklede lancetformige Endeplader; Hpreapparatet ved 
Basis af den indre Plade rudimentsert. 
Almindelige Bemserkninger. Af de tidligere be- 
kjendte Mysidesbegter svnes denne nye Slsegt, navnlig kvad 
Munddelene angaar, at slutte sig mermest til SI. Mysideis 
G. 0. Sars, men skiller sig bestemt fra samme ved den 
rudimentajre Beskaffenhed af 0inene samt det i den indre i 
Haleplade beliggende Horeapparat. fremdeles ved Fpddernes 
afvigende Bygning og den meget eiendommelige Form af 
det midterste Halevedhseng. 
Enkelte vigtige Punktor, navnlig Forboldet af Hannens 
Bagkropslemmer, bar vistnok endnu ikke kunnet oplyses 
paa Grand af det utilstrsekkelige foreliggende Materiale; 
men allerede de ovenfor fremkaevede Oharacterer synes mig 
dog at vsere af tilstrsekkelig Ysegt til herpaa at maatte be- 
grunde en generisk Adskillelse. 
Sbegten indebolder for Tiden kun en enkelt Aft, som 
desvaerre kun er repnesenteret af to meget mutilerede Ex- 
emplarer, begge Hunner. 
9. Pseudomysis abyssi, G. 0. Sars, n. sp. 
(PI. V, Fig. 13—21, PI. XX, Fig. 18—20). 
Pseudomysis abyssi, Gr. 0. Sars, Crustacea et Pycnogonida nova etc. 
No. 4. 
Artscharaeteristik. Bygskjoldet fortil betydelig bre- 
bredere end Bagkroppen, med Panderauden i Midten ud- 
draget i en skarp, rostrumlignende Spids. 0inene meget 
smaa, stumpt koniske, ved Spidsen fortil forsynet med et 
tandformigt Fremspring. Iste Par Foleres Skaft smalt 
cylindriskt med Iste og sidste Led af samme Storrelse. 
2det Par F oleres Blad dobbelt saa langt som Iste Pars 
Skaft, smalt lancetformigt, med Spidsen stumpt tilrundet. 
Fcfdderne alle af ens Laengde. med det ydre Parti omtrent 
saa langt som det foregaaende Led og delt i 7 — 8 korte, 
Gen. Pseudomysis, G. 0. Sars, 1880, n. 
Crustacea et Pycnogonida nova etc. 
G-eneric Character. — Body thickset in form. Car- 
apax large and broad, projecting anteriorly in the middle. 
Eyes quite rudimentary, without either pigment or visual 
elements. First pair of antennse exhibiting the usual ap- 
pearance. Scale of 2nd pair lanceolate, and beset round 
the edges with bristles. Oral appendages presenting con- 
siderable resemblance to those in the genus Mysideis. Legs 
comparatively small and feeble, with a multiarticulate tarsus, 
and having the terminal claw imperfectly developed ; natatory 
branches remarkably elongate. Telson exceedingly short, 
lamelliform, incised posteriorly. Outer caudal appendages 
with well-developed lanceolate terminal plates; auditory ap- 
paratus at the base of the inner plate rudimentary. 
General Remarks. — - Of the previously known genera 
of Mysidians, this new genus — • in particular as regards the 
oral appendages — would appear to approximate closest the 
genus Mysideis, G. O. Sars, but is, however, plainly distin- 
guished from it by the rudimentary character of the eyes 
and of the auditory apparatus placed within the inner caudal 
plate, moreover by the deviating structure of the legs and 
the very peculiar form of the telson. 
A few important points, more especially as regards 
the structure of the pleopoda in the male, have, it is true, 
not yet been elucidated, owing to the insufficient material 
obtained; but even the characters specified above are, I 
opine, amply sufficient to warrant generic distinction. 
The genus comprises at present but a single species, 
which, unfortunately, is represented by only two very muti- 
lated specimens, both females. 
9. Pseudomysis abyssi, G. 0. Sars, n. sp. 
(PI. V, figs. 13 — 21; PI. XX, figs. 18—20). 
Pseudomysis abyssi, Cr. 0. Sars, Crustacea et Pycnogonida nova etc., 
No. 4. 
Specific Character. — Oarapax much broader an- 
teriorly than posterior division of body, with the frontal 
margin produced in the middle to a sharp, rostrum-like 
point. Eyes very small, obtusely conical, furnished an- 
teriorly at the point with a dentiform projection. Peduncle 
of 1st pair of antenna; slender-cylindric, with the first and 
last joints equal in size. Scale of 2nd pair of antenna; twice 
as long as peduncle of 1st pair, slender-lanceolate, with 
the point obtusely rounded. Legs all of one length, with 
the outer portion about as long as the preceding joint, 
