Ill 



klin bestaaende af to simple Lameller, mien enhver 

 Bevælming'. Fodderne hos Hunnen 12 Par, hos 

 Hannen 10 Par; den dorsale Lap af Exopoditen paa 

 de 7 forreste Par enormt lulviklet, paa 9de og lUde 

 Far hos Hnnnen omformet til evHndriske omboiede 

 Strenge. Æggene omgivne af en simpel Skal og 

 sammenhobede nnder den bagre Del af Hunnens 

 Skal til 2 kageformige Masser. Larven ved sin 

 Fdklækning forsynet med et stort, tladt Rygskjold. 



Bemærkninger. — Denne Slægt er opstillet i 

 Aaret 1.S4G af Loven for en sydafrikansk Art, L. 

 Wahlbeygi. Den kort Tid efter af Liévin opstillede 

 Slægt Hedessa er identisk med Loven's Slægt. Man 

 kj ender ialt 8 eller 9 forskjellige Arter, som dog 

 ikke alle er tilstrækkeligt eharacteriserede. Slæg- 

 ten synes at have en meget vid geographisk Ud- 

 bi'edning, idet Repræsentanter er fundue i samtKge 

 Verdensdele. Hos os forekommer kun én Art. 



Limnetis brachyurus, (Mull) 

 (Pl. x\'iJi— xx;. 



Lyncms hrachyurus, O. F. jMiiller, Entoniostraca, p. SO, Tab. 



VIII, figs. 1—12. 

 Hedessa Sieholdi. Liévin, Schriften des natnrf. Gesellsch. in 



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

 Hedessa bnichyiira, .Siebold, Preuss. Provinciulbl. ISl'.i, Bd. VII, 



Heft 3, p. 198. 

 Limnetis hranchyurus, Grube, Archiv f. Xatnrgeschiclite, Bd. 



XIX, p. 71, Tab. V— VII. 



Artscharacter. — Skallen, seet fra Siden, rund- 

 agtig, næsten ligesaa hoi som lang, den stor.ste 

 Holde fortil, Rygkanten noget skråa og kun svagt 

 buet, de frie Kanter af Valvlerne dannende en uaf- 

 bi'udt Bue, Forenden meget bredere en Bagenden: 

 — seet ovenfra bredt ægformig, den storste Bredde 

 bag Midten. Langs Dorsalsiden en dyb Fure, i 

 hvis Bund Valvlerne er forbundne med hinanden. 

 Hovedet hos Hunnen næsten saa langt som Truneus, 

 Dorsalkanten jevnt buet, Rostrum endende i en 

 skarpt tilspidset Fortsats, ved Ba.sis af hvilken der 

 er to korte laterale Fremspring. Hovedet hos Han- 

 nen kortere, Rostrum tvært afkuttet, uden nogen 

 terminal Spids. Haledelens Endeflige lios Hannen 

 betydelig mere forlængede end hos Hunnen. Iste 

 Par Fodder hos Hannen med Haanden næsten qva- 

 dratisk og bevæbnet langs Inderkanten med en Rad 

 af 9 stærke, jjladefonnige Tænder, Kloen leformigt 

 krummet og tilspidset i Enden, den .subapicale Lap 

 temmelig smal, kloformigt indadkrummet, og borste- 

 besat alene i Spidsen. Farven mork olivengren. 

 Længdeu af Skallen indtil 4V'3 mm. 



any tentacular projection. Second pair of maxillæ 

 consisting of only two simple lamellæ, quite unarmed. 

 Twelve pairs of legs in the female, in the male lU ; 

 dorsal lobe of the exopodite in the 7 foremost pairs 

 enormously developed, in the 9th and 10th pairs, in 

 the female, transfornfed into cylindrical cords bent 

 at the tip. Eggs surrounded l)y a simple shell, 

 and accumulated beneath the hinder part of the 

 female's shell, into 2 cake-like masses. Tlie larva, 

 when hatrhed, furnished with a large, flat carapace. 

 Remarks. — This genus was established in the 

 year 184(i, by Loven, for a South African species, 

 L. WciJiHwrj/i. The genus Hedessa, established a 

 short time after bj' Liévin is identical with Loven's 

 genus. Eight or nine different species are already 

 known, not all. however, sufriciently characterised. 

 The genus seems to have a very wide geographical 

 distribution, representatives being found in all quar- 

 ters of the glolje. Only (ine species occurs in this 

 country (Xorwav). 



Limnetis brachyurus, (Miill ) 



(PI. XVIII— XXJ. 



Lynceits hraclu/itrns, O. F. .Miiller, Entoniostraca, p. 69, Tab. 



VIII, figs. 1—12. 

 Hedessa Sieholdi, Liévin, Schriften des naturf. Gcsellsch. in 



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

 Hedessa brachi/nra, .Siebold, Preuss. Provincialbl. 1849, Bd. VII, 



Heft 3, p. 198. 

 Limnetis hranchyurus, Grube, Archiv f, Xaturgescliiclite, Bd. 



XIX, p. 71, Tab. V— VIL 



Specific Characters. — Shell, seen from the 

 side s])heroidal, almost as high as it is long, 

 the greatest height being in front; dorsal margin 

 rather oljli(|ue and only slightly arched, the free 

 edges of the valves forming an uninterrupted curve : 

 the anterior end much broader than the postei'ior. 

 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 aljruptly truncated witli- 

 (Uit any terminal point. Terminal lobes of the caudal 

 |)art in the male considerably more produced than 

 in the female. Fir.st pair of legs in the male with 

 the hand almost s([uare, 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 ch^tlied with bristles only 



