69 



Polyartemia forcipata, FL^elier. 



(Fl. I\ & X). 



Polyartemia forclpata, Fisolier, Middendoi'ff's Sibirische Reise, 

 Bd. ■>. Zoologie, p. 154, Tab. Vll, Fig. 24— -'8. 



Artscharacter. — Legemet smalt cylindriskt, 

 næsten jevnt tvkt lio.s Hunnen, noget afsmalnende 

 bagtil hos Hannen. Hovedet hos Hunnen forholds- 

 vis lidet og afrundet fortil, hos Hannen betydelig 

 bredere og endende med 2 stumpt coniske, nedad- 

 krummede Frontalfortsatser. Halen og Kjonsringene 

 tilsammen neppe mere end halvt saa lang som den 

 fodbærende Del af Krop])en. Hunnens Ægbeholder 

 bredt afrundet fortil med et knudeformigt Frem- 

 spring til hver 8ide Hannens ydre Kjonsvedhæng 

 simpelt evlindriske og omtrent af Halens halve 

 Længde. Øinene kolleformige, omtrent af Længde 

 som Hovedets halve Tværdiameter. Første Par Fø- 

 lere forholdsvis smaa, kortere end Øinene. Andet 

 Par Feiere hos Hunnen betydelig kortere end Ho- 

 vedet, endende i en triangulær Flig; samme Folere 

 hos Hannen særdeles store, tregrenede, de 2 forreste 

 Grene tangformigt krummede i Enden og fint rili- 

 erede i den indre Kant, den bagerste Llren kort, 

 lige nedad rettet og tæt haaret i Enden. Hale- 

 pladerne bredt latu^etformige, omtrent ddbbelt saa 

 lange som de er lu'ede ved Basis. Legemet gjennem- 

 sigtigt med svagt gronligt, blaaligt eller rodligt 

 Skjær. Hannen sædvanlig Ij's gulagtig. Hunnens 

 Kjonsringe oventil med 2 iiltranunrinlilaa kantede 

 Pletter, mellem hvilke er 'l smale Striber af samme 

 Farve, Ægbeholderen orangefarvet nedentil. Hun- 

 nens Længde indtil Ki mm. Hannens 10 mm. 



Bemærkninger. — Denne eiendommelige Phyllo- 

 pode blev forst o]idaget under Middendorffs Reise i 

 Sibirien og er kortelig beskrevet under ovenstaaende 

 Navn af S. Fiseher, sammen med andre under Rei- 

 sen indsamlede Entomostraceer. Den er senere 

 ogsaa gjenfunden af andre Forskere, uden at dog 

 endnn nogen mere udforlig Beskrivelse er leveret. 



Beskrivelse af Hunnen. 



Længden af Legemet, fra Panderandeu til Eriden 

 af Halebladene, naar op til 1(5 mm. Dog tinder man 

 den, saaledes som Tilfældet er med andre Phvllo- 

 poder, slægtsmoden læuge for den har naaet denne 

 Størrelse. 



Legemet er (se Tab. IX. Fig. 1 og 2) slankt, 

 oylindriskt, og næsten af ens Bredde, dog hos fuldt 

 udviklede Individer kjendeligt ops\-ulmet ■ bagtil i 

 Kjonsregionen. . Man kan adskille de samme Krops- 



Polyartemia forcipata. Fisrher. 



(Pl. IX Å- X). 



Poli/arfeiiiia forcqxifa, Fischer, MiddendorfF's Siberische Reise, 

 Bd. 2. Zoologie, p. lo4, Tab. III, fig. 24— 2S. 



Specific characters. — l>ody narrow cylindrical, 

 of almost uniform thickness in the female, tapering 

 in the male. Head in female com]iaratively small 

 and rounded in front, in male considerably broader, 

 and ending in two l)luntly conical, deeui'ved fron- 

 tal processes. Tail and genital segments together 

 scarcely more than half as long as the pedigerous 

 part of the bod}-. Marsu])ium of female broadly 

 roiinded in front with a nodiform protuberance on 

 each side. Exteriuil sexual appendages of male 

 simjile cylindrical, and about half the length of the 

 tail. Eyes club-shaped, about the lengtli of half 

 the transverse diameter of the head. First pair of 

 antennæ comparatively small, shorter than the eyes. 

 Second pair of antennæ in female considerably 

 shorter than the head, and ending in a triangular 

 lappet; in male very large, tripartite, the two fore- 

 most rami being curved like a forceps at the end, 

 and finely ciliated on the inner margin, the hind- 

 most ramus short, pointing straight inwards, and 

 densely hairy at tlie extremity. Caudal lamellæ 

 broadly lance(date, about twice as hmg as the^^ are 

 broad at the base. Body transparent, with a faint 

 green, blue or red tinge; that of male generally 

 pale yellow, tienital segments of female above with 

 2 angular ultramarine-blue patches, between which 

 there are two narrow stripes of the same colour. 

 Marsupium orange-coloured behiw. Lengtli of female 

 up to Ki mm, that of male, 10 mm. 



Remarks. — This jieculiar Pliyllopod was first 

 discovered during Middendorff's journey in Siberia, 

 and is briefly described under the above name by 

 S. Fischer, together with other Eutomostraca col- 

 lected during that journe\'. It was subse(|uently 

 also found by other naturalists, notwithstanding 

 which, no more detailed descrijition has as yet lieen 

 furnished. 



Description of the Female. 



The lengtli of the body, from the frontal mar- 

 gin to the end of the caudal lamellæ, attains to llJ 

 mm. It is found, however, as is also the case with 

 other Pliyllopoda, sexually mature long before it has 

 attained this size. 



The body (see I'l. IX, figs. 1 and 2) is slender, 

 cylindrical, and of almost unitorm breadth through- 

 out, though, in fully developed animals, perceptibly 

 distended posteriorly , in the sexual region. The 



