Hunnen kort trianguler, hos Hannen betydelig ster- 
kere uddraget og nesten leformig indadkrummet. 
Hunnens Agbeholder serdeles forlenget, rekkende 
neesten til Enden af nestsidste Halesegment. Han- 
nens ydre Kjonsvedheng cylindriske, forsynede ved 
Basis fortil med 2 fremspringende Flige, mellem 
hvilke der er en dyb Indbugtning. Legemet hos 
begge Kjon gjennemsigtigt, med et mere eller min- 
dre tydeligt gronligt eller redligt Anstrog. Hun- 
nens Lengde indtil 18 mm:, Hannens 23 mm. 
Bemerkninger. Denne Art er allerede i 1780 
af O. Fabricius anfort fra Gronland, men urigtigt 
identificeret med Br. stagnalis Scheeffer. ‘Senere er den 
under den oventor anforte Species-Benevnelse kjende- 
ligt beskrevet og afbildet af O. Fr. Miiller i hans 
bekjendte Veerk, Fauna danica. De af Prof. Verrill 
som B. grgnlandica og arctica opforte Former har 
senere vist sig at vere identiske med nerverende 
Art, og det samme er utvivlsomt ogsaa Tilfeldet 
med’ B. middendorfianus Fischer, Af de 2 nordame- 
rikanske Arter beskrevne af Packard, synes B. colo- 
radensis at komme meget ner den her omhandlede 
Art, medens B. Lindahli skiller sig mere kjendeligt, 
navnlig ved de betydelig sterkere forlengede Hale- 
grene. 
Generel Beskrivelse. Legemet er hos begge 
Kjon (se Pl. VE, Fig. 1—4) smalt og forlenget, ne- . 
sten ormformigt, med serdeles tynde og boielige 
Integumenter, samt inddelt i tydelige Segmenter, 
Man kan adskille 3 temmelig skarpt begraendsede 
Kropsafsnit, nemlig Hoved, Midtkrop og Bagkrop 
eller Hale. 
Hovedet bestaar igjen af 2 Partier, et forreste 
og et bagerste, skilte ved en tydelig over Rygsiden 
gaaende Tversutur. Det forreste Parti er noget 
opsvulmet, nesten kugleformigt, og mere eller min- 
dre sterkt nedboiet. Det berer Ginene og 2 Par 
Folere, samt fortseetter sig nedentil i Overleben. 
Til det bagre Parti eller Nakkedelen horer de ovrige 
Munddele. Af disse er mest ioinefaldende de kraf- 
tigt udviklede Kindbakker, der som et Par Boiler 
omgiver Hovedet paa Greendsen mellem dettes 2 Af 
snit, og hvis baadformige Corpora danner til hver | 
Side et tydeligt convext Fremspring, sely bemerke- 
ligt, naar Dyret sees ovenfra. lLige bag Kind- 
bakkerne sees til hver Side af Nakkesegmentet en 
S-formigt bugtet Figur, den saakaldte Skalkjertel, 
hvis bagre Del omsluttes af en lidt fremspringende 
Hudfold, den forste svage Antydning til det hos 
andre Phyllopoder saa sterkt udviklede Rygskjold 
eller Skal. Ventralt udgaar fra Nakkesegmentet de 
2 Par Kjever. 
42 
which is bluntly rounded. Branchial feet with the 
outer lobe of the endopodite, in female, short tri- 
angular; in male considerably more drawn out, 
and almost falciformly curved inwards. Mar- 
supium of female greatly prolonged, reaching al- 
most to the extremity of the penultimate caudal 
segment. Outer sexual appendages of male eylin- 
drical, furnished in front, at the base, with 2 
projecting flaps, between which there is a deep 
sinus. 
more or less distinct greenish or reddish tinge. 
Length of female up to 18 m. m.; that of male 
23 m. m. 
Remarks. This species is, as early as 1780, 
recorded by A. Fabricius from Greenland, but errone- 
ously identified with Br. stagnalis, Scheffer. Subse- 
quently it has been, under the above-named specific 
designation, recognizably described and illustrated 
by O. Fr. Muller in his well-known work, Fauna 
danica. The forms established as B. grgnlandica and 
arctica by Prof. Verrill, have subsequently shown 
themselves to be identical with the present species, — 
and the same is also indubitably the case with 
B. middendorfianus, Fischer. Of the 2 North Ame- 
rican species described by Packard, B. coloradensis 
appears to approach pretty closely the species here 
described, whilst B. Lindahli distinguishes itself more 
noticeably, especially by the considerably more 
prolonged caudal rami. 
General description. The body is, in both sexes, 
(see Pl. VI, figs. 1—4) narrow and prolonged, almost 
vermiform, with particularly thin and flexible inte- 
guments, and is divided into distinct segments. © 
We can distinguish 3 pretty sharply defined divi- 
sions of the body, viz., the cephalon, the mesosome, 
and the metasome or tail. 3 
The cephalon, again, consists of 2 parts, an an- 
terior and a posterior one, separated by a distinct 
transversal suture passing across the dorsal side. 
The foremost part is somewhat swollen, almost glo- 
bular, and more or less strongly bent downwards. 
It carries the eyes and the 2 pairsof antenne, and 
is continued downwards in the upper lip. The other 
oral parts pertain to the posterior, or cervical part. 
Of these, the most striking are the powerfully de- 
‘veloped mandibles, which like a pair of bows sur- 
round the head on the limit between its 2 divisions, 
and whose cymbiform corpora form on either side a 
distinctly convex prominence, even noticeable when 
the animal is viewed from above. Just behind the 
mandibles there is seen, on either side of the cervi- 
cal segment, an S-formed flexuous figure, the so-called 
shell-gland, whose posterior part is enclosed by a 
slightly projecting integumental fold, the first faint 
indication of the, in other Phyllopods so strongly 
developed carapace or shell. The 2 pairs of 
Body transparent in both sexes, with a. 
