117 



kun bestaaende af to simjile Lamellei', inlcn fiihver 

 Bevæbninp;. Fodderne hos Hunnen 12 Par, hos 

 Hannen 10 Par; den dorsale La]) af Exopoditen paa 

 (le 7 forreste Par enormt udvikh't, paa 'Jde op; lOde 

 Far hos Hunnen omformet til cylindriske oniboiede 

 Strenge. Æggene omgivne af en simpel Skal og 

 sammenhobede under den bagi-e Del af Hunnens 

 Skal til 2 kageformige Masser. Larven ved sin 

 Lalklækning forsynet med et stort, fladt liygskjold. 



Bemærkninger. — Denne Slægt er opstillet i 

 Aaret l.S4t) af Loven for en sydafrikansk Art, L. 

 WaMbergi. Den kort Tid efter af Liévin opstillede 

 Slægt Hedessa er identisk med Lovén"s Slægt. Man 

 kjender ialt s eller i) forskjellige Arter, som dog 

 ikke alle er tilstrækkeligt characteriserede. Slæg- 

 ten synes at have eu meget vid geographisk Ud- 

 bredning, idet Repræsentanter er 1'undne i samtlige 

 Verdensdele. Hos os forekommer kun én Art. 



Limnetis bracliyurus, (^Lnll) 



,,P1. XVIII— XX,. 



LijnccHii hrarlu/ninis, O. F. Muller, Entoniostmea, p. €'.i, Tab. 



VIII, fifjs. 1 — 1-.'. 

 Hedessa Sieholdi, Liévin, Jichriften des natuif. Gesellsch. in 



Danzig, Bd. IV, Heft II, p. 4, Tab. I. II. 

 Hedessa brachyura, Siebold, Preuss. Provincialbl. 1 8-l'.i, Kd. VII, 



Heft 3, p. ]9S. 

 Limnetis brtincJii/urits, Grube, Arohiv f. Xaturgescliichte, Bd. 



XIX, p. 71, Tab. V— VII. 



Artscharacter. — Skallen, seet fra Siden, rund- 

 agtig, iiæsten ligesaa hoi som lang, den største 

 Hoide fortil, Rvgkanten noget .skråa og kun svagt 

 Iniet, de frie Kanter af Valvlerne dannende en naf- 

 lirudt Bue, Forenden meget bredere en Bagenden: 

 — seet ovenfra bredt ægformig, den største Bredde 

 bag Midten. Langs Dorsalsiden en dyb Fure, i 

 hvis Bund Valvlerne er forbundne med hinanden. 

 Hovedet hos Hunnen næsten saa langt som Truncus, 

 Dorsalkanten Jevnt buet, Rostrum endende i en 

 skarjit tilspidset Fortsats, ved Basis af hvilk-eii der 

 er to korte laterale Fremspring. Hovedet hos Han- 

 nen kortere. Rostrum tvært afkuttet, uden nogen 

 terminal S])ids. Haledelens Kndeliige hos Hannen 

 betydelig mere forlængede end hos Hunnen. Iste 

 1'ar Fodder hos Hannen med Haanden næsten (|va- 

 dratisk og bevæbnet langs Inderkanten med en Rad 

 af U stærke, ])ladeformige Tænder, Kloen leformigt 

 krummet og tilspidset i Knden, den suba])icale Lap 

 temmelig smal, kloformigt indadkrummet, og borste- 

 besat alene i Spidsen. Farven mork olivengren. 

 Længden af Skallen iiidril 4' ^ mm. 



any tentacular projection. Second pair of maxillæ 

 consisting of onU' two simjile lamellæ, (juite unarmed. 

 Twelve ])airs of legs in the female, in the male 10; 

 dorsal lol)e of the e.xopodite in the 7 foremost jjairs 

 enormoush- 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 1840, b^- Loven, for a South African s])ecies, 

 L. Wahlbergi. The genus Hedessa, established a 

 short time after b3' Liévin is identical with Lovens 

 genus. Eight or nine diiferent species are already 

 known, not all, however, sufficiently characterised. 

 The genus seems to have a very wide geographical 

 distribution, representatives being found in all (juar- 

 ters of the globe. Only one species occurs in this 

 countrj- (Norway). 



Limnetis brachyurus, (Mull.) 



(PI. XVIII— XX). 



Lynceus hrachyurns, O. F. Miiller, Entomostraca, p. (59, Tab. 



VIII, figs. 1 — 12. 

 Hedessa Sieboldi, Liévin, Schriften des uaturf. Gesellsch. in 



Danzig. Bd. IV, Heft II, p. 4, Tab. I, II. 

 Hedessa brachyura, Siebold, Preuss. Provincialbl. 1819, Bd. VII. 



Heft 3, p. 198. 

 Limnetis branehyurus, Grube, Arcliiv f Xaturgescliiclite, Bd. 



XIX, p. 71. Tab. V— VH. 



Specific Characters. — Shell, seen from the 

 side sjiheroidal, almost as high as it is long, 

 the greatest height being in front; dorsal margin 

 rather oblitjue 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 fenutle almost as long as the trunk, 

 dorsal margin evenly curved, rostrum ending in a 

 sharply pointed ])roicction, at the base of whicii 

 there ai'e two short lateral j)rominences. Head in 

 the male shorter, rostrum abruptly truncated with- 

 out any terminal ])oint. Terminal lobes of the caudal 

 part in the male considerably more ])roduced than 

 in the female. First ])aii' of legs in the male witii 

 the hand almost sipiare, and armed along the inner 

 margin with a row of '.• strong, lamellar den- 

 ticles; claw fahiformly curved, and pointed at 

 the extremity; sub-apical lolie rather narrow, bent 

 inwards like a claw, and clothed with bristles only 



