64 



men er, som hos Brancliinecta, kun indskrænket til 

 sidste Halesegment, og viser en lignende Bygning 

 som hos denne Slægt. 



Nervesystemet synes idethele at være bj'^gget 

 paa samme Maade som hos Branchhiecta, alene med 

 den Forskjel, at Buggangliekjæden her er sammen- 

 sat af et betydelig storre Antal Ganglier, overens- 

 stemmende med det storre Antal Segmenter i For- 

 kroppen. 



Ovarierne (Tab. X, Fig. 12, 13, osv.) er her kun 

 indskrænket til Kjønsregionen, idet de ligger til 

 hver Side ved Basis af Ægbeholderen, nden at 

 strække sig ind, hverken i Forkroppen eller i den 

 bagenfor Ægbeholderen liggende Del af Halen. De 

 danner 2 korte cylindriske Sække (Fig. 14), i hvis 

 Indre ialmindelighed kun iindes en enkelt Række af 

 sig ndviklende større Æg fyldte med grøn Blomme- 

 masse, og desfoniden, mere uregelmæssigt fordelte, 

 et Antal af meget smaa klare Celler med tj-deligt 

 fremtrædende Kjerne. Omtrent fra Midten af hvert 

 Ovariums indre Kant udgaar Æglederen, der viser 

 paa Midten en stærk, sækformig Udvidning og mun- 

 der i det indre af Ægbeholderen. Mundingen er 

 delvis omgivet af en meget voluminos Kjertelmasse 

 (Fig. 12, 13, gl), der strækker sig igjennem hele Æg- 

 beholderens Længde, og som afgiver Stoffet til den 

 stærke Skal, hvormed Æggene her omgives. De 

 modne af Ovarierne udkomne Æg ligger uregelmæs- 

 sigt ordnede i Ægbeholderens Siderum (se Tab. IX, 

 Fig. 1 og 2) og udtommes med visse Mellemrum 

 gjennem dens klapformige Munding. De er da (se 

 Tab. X, Fig. 15) omgivne af en temmelig tyk og 

 meget fast chitinos Skal, der ved stærk Forstørrelse 

 viser sig uregelmæssig reticuleret. Ægindholdet er 

 ensformigt kornet og af en meget mørk grøn, i det 

 brunlige spillende Farve. Nogen Segmentering af 

 Ægget har jeg ikke kunnet ])aavise. 



Testes (Tab. X, Fig. K!, t) indtager omtrent 

 samme Plads som Ovarierne, skjondt de strækker 

 sig lidt ind i den bag Kjønsringene liggende Del af 

 Halen. De har Formen af 2 smale Sække, tilspid- 

 sede i hver Ende, og noget tykkere fortil end bag- 

 til. Noget bagenfor den forreste Ende udgaar fra 

 den nedre Side Sædlederne, der, som lios Branchi- 

 necta, danner en temmelig stærk, tvedelt Udvidning 

 (vd), hvorpaa de hver antager Formen af en trang 

 Kanal. Denne gjør en stærk slyngeformig Bøining, 

 inden den træder ind i de ydre Kjønsvedhæng, paa 

 hvis Spids den udmunder. 



Fdvikliug. 



Ogsaa af denne Form har jeg leilighedsvis havt 

 Anledning til at undersoge Uere Udviklingstrin, 

 uden at det dog endnu har lykkets mig at faa stu- 

 deret den hele Udvikling fra forst af. 



The rectum, as in Brancliinecta, is limited to the 

 last caudal segment, and exhibits a structure similar 

 to that in the above-named genus. 



The nervous system seems, on the whole, to be 

 constructed in the same manner as in Brancliinecta., 

 with the one difference that the ventral ganglion 

 chain is composed of a considerably larger number 

 of ganglia, corresponding to the greater number of 

 segments in the anterior part of the body. 



The ovaries (PI. X, figs. 1 2, 13, ov) are confined 

 to the genital region, and lie one on each side of 

 the base of the marsupium, without extending either 

 into tlie anterior part of the body, or into the 

 caudal region behind the marsupium. They form 

 two short cylindrical bags (fig. 14) within which 

 there is generally only a single row of eggs under- 

 going development, and filled with a green yolk-mass, 

 and also, more ii'regularly dispersed, a number of 

 minute clear cells with distinctly conspicuous nuclei. 

 From about the middle of the inner edge of each 

 ovary, issiies the oviduct, with a large sac-like dila- 

 tation in the middle, and opens into the inside of 

 the marsupium. The mouth is partially surrounded 

 by a very voluminous glandular mass (figs. 12, 13, 

 gl), which extends through the entire length of the 

 marsupium, and secretes the substance for the 

 strong shell with which the %gg becomes here sur- 

 rounded. The mature ova that have come out of 

 the ovary, are irregularly- arranged in the lateral 

 spaces of the marsupium (see PI. IX, figs. 1, 2) and 

 are evacuated at certain intervals through the 

 valve-like mouth. They are then (see PL X, fig. 15) 

 enveloped in a tolerably thick, and very firm chiti- 

 noiTS shell, which on being highly magnified appears 

 irregularly reticulated. The contents of the ovum 

 are uniformly granulose and of a very dark green 

 colour with a tinge of brown. I have been unable 

 to discover any segmentation of the ovum. 



The testes (PI. X, fig. 16, t) occupy about the 

 same place as the ovaries, though they extend a 

 little way into that part of the tail h'ing lieliind 

 the genital segments. They are in the form of 2 

 narrow bags, pointed at both ends and rather thicker 

 in front than behind. From the inferior side, a little 

 behind the anterior end, issue the efi'erent ducts 

 forming, as in -Brffwo/*mef fø, a rather strong, bipartite 

 expansion (vd), whereupon each assumes the form 

 of a narrow channel. This makes a sjnral curve 

 before it enters the external sexual appendage, at 

 the point of which it opens. 



Developinent. 



I have occasionally had the opportunity of exa- 

 mining several developmental stages of this form 

 also, although I have not yet succeeded in studying 

 its whole development from the very beginning. 



