kun bestaaende af to simple Lameller, uden enhver 
Bevebning. Fodderne hos Hunnen 12 Par, hos 
Hannen 10 Par; den dorsale Lap af Exopoditen paa 
de 7 forreste Par enormt udviklet, paa 9de og 10de 
Par hos Hunnen omformet til cylindriske omboiede 
Strenge. Aiggene omgivne af en simpel Skal og 
sammenhobede under den bagre Del af Hunnens 
Skal til 2 kageformige Masser. Larven ved sin 
Udklekning forsynet med et stort, fladt Rygskjold. 
Bemerkninger. — Denne Slegt er opstillet i 
Aaret 1846 af Lovén for en sydafrikansk Art, L. 
Wahlbergi. Den kort Tid efter af Liévin opstillede 
Slegt Hedessa er identisk med Lovén’s Slegt. Man 
kjender ialt 8 eller 9 forskjellige Arter, som dog 
ikke alle er tilstreekkeligt characteriserede. Sleg- 
ten synes at have en meget vid geographisk Ud- 
bredning, idet Representanter er fundne i samtlige 
Verdensdele. Hos os forekommer kun én Art. 
Limnetis brachyurus, (Miill.) 
(Pl. XVUI—XxX). 
Lynceus brachyurus, O. F. Miller, Entomostraca, p. 69, Tab. 
VIII, figs. 1—12. 
Hedessa Sieboldi, Litvin, Schriften des naturf. Gesellsch. in 
Danzig, Bd. IV, Heft II, p. 4, Tab. I, IL. 
Hedessa brachywra, Siebold, Preuss. Provincialbl. 1849, Bd. VII, 
Heft 3, p. 198. 
Limnetis branchyurus, Grube, Archiy f. Naturgeschichte, Bd. - 
XIX, p. 71, Tab. V—VII. 
Artscharacter. — Skallen, seet fra Siden, rund- 
agtig, neesten ligesaa hoi som lang, den storste 
Hoide fortil, Rygkanten noget skraa og kun svagt 
buet, de frie Kanter af Valvlerne dannende en uaf- 
brudt Bue, Forenden meget bredere en Bagenden: 
— seet ovenfra bredt #gformig, den storste Bredde 
bag Midten. Langs Dorsalsiden en dyb Fure, i 
hvis Bund Valvlerne er forbundne med_hinanden. 
Hovedet hos Hunnen nesten saa langt som Truncus, 
Dorsalkanten jevnt buet, Rostrum endende i en 
skarpt tilspidset Fortsats, ved Basis af hvilken der 
er to korte laterale Fremspring. Hovedet hos Han- 
nen kortere, Rostrum tvert afkuttet, uden nogen 
terminal Spids. Haledelens Endeflige hos Hannen 
betydelig mere forlengede end ~hos Hunnen. Iste 
Par Fodder hos Hannen med Haanden nesten qva- 
dratisk og beveebnet langs Inderkanten med en Rad 
af 9 sterke, pladeformige Tender, Kloen leformigt 
krummet og tilspidset i Enden, den subapicale Lap 
temmelig smal, kloformigt indadkrummet, og borste- 
besat alene i Spidsen. Farven mork olivengron. 
Lengden af Skallen indtil 41/2 mm, 
117 
any tentacular projection. Second pair of maxilla 
consisting of only two simple lamelle, quite unarmed. 
Twelve pairs of legs in the female, in the male 10; 
dorsal lobe of the exopodite in the 7 foremost pairs 
enormously developed, in the 9th and 10th pairs, in 
the female, transformed into cylindrical cords bent 
at the tip. Eggs surrounded by a simple shell, 
and accumulated beneath the hinder part of the 
female’s shell, into 2 cake-like masses. The larva, 
when hatched, furnished with a large, flat carapace. 
Remarks. — This genus was established in the 
year 1846, by Lovén, for a South African species, 
L. Wahlbergi. The genus Hedessa, established a 
short time after by Liévin is identical with Lovén’s 
genus. Eight or nine different species are already 
known, not all, however, sufficiently characterised. 
The genus seems to have a very wide geographical 
distribution, representatives being found in all quar- 
ters of the globe. Only one species occurs in this 
country (Norway). 
Limnetis brachyurus, (Miill.) 
(Pl. XVUI—XX). 
Lynceus brachyurns, O. F. Miiller, Entomostraca, p. 69, Tab. 
VIII, figs. 1—12. 
Hedessa Sieboldi, Lievin, Schriften des naturf. Gesellsch. in 
Danzig, Bd. IV, Heft II, p. 4, Tab. I, Il. 
Hedessa brachyura, Siebold, Preuss. Provincialbl. 1849, Bd. VII, - 
Heft 3, p. 198. 
Limnetis branchyurus, Grube, Archiv f. Naturgeschichte, Bd. 
XIX, p. 71, Tab. V—VIL. 
Specific Characters. — Shell, seen from the 
side spheroidal, almost as high as it is long, 
the greatest height being in front; dorsal margin 
rather oblique and only slightly arched, the free 
edges of the valves forming an uninterrupted curve: 
the anterior end much broader than the posterior. 
Seen from above, the shell is broadly ovate, with 
the greatest breadth behind the middle. Along the 
dorsal surface, runs a deep furrow, at the bottom 
of which the valves are connected with each other. 
Head in the female almost as long as the trunk, 
dorsal margin evenly curved, rostrum ending in a 
sharply pointed projection, at the base of which 
there are two short lateral prominences. Head in 
the male shorter, rostrum abruptly truncated with- 
out any terminal point. Terminal lobes of the caudal 
part im the male considerably more produced than 
in the female. First pair of legs in the male with 
the hand almost square, and armed along the inner 
margin with a row of 9 strong, lamellar den- 
ticles; claw falciformly curved, and pointed at 
the extremity; sub-apical lobe rather narrow, bent 
inwards like a claw, and clothed with bristles only 
