128 



og skraat bagudrettede. Nerverne for Aarenie (a -') 

 iidspringer ogsaa lier fra de fra Hjernegangliet bagud 

 gaaende Commissvirer. Bnggangiiekjæden (Tab. XX, 

 Fig. 19) ligner samme hes Limnaclia, dog med den 

 Forskjel, at Nerve-stammerne er forholdsvis stærkere 

 og ligger noget nærmere sammen. Antallet af 

 gangliose Opsvulmninger er selvfølgelig, i Overens- 

 stemmelse med det langt ringere Antal Fodpar, 

 mindre end hos Limnaclia. 



Ovarierne (se Tab. XIX, Fig. 1) er af betydelig 

 Storrelse, strækkende sig til hver Side af Tarmen 

 gjennem hele Tranens. De viser et stærkt lappet 

 Udseende, idet Ægfolliklerne grupperer sig drueklase- 

 formigt omkring Ovarialrorene (se Tab. XX, Fig. 13). 

 Æglederen udgaar fra den bagerste Del af hvert 

 Ovarium og synes at udmunde umiddelbart under 

 de ovenomtalte trefligede dorsale Blade. Paa dette 

 8ted ser man nemlig ofte større Masser af modne 

 Æg samlede. Som hos Limnadia, indeholder hver 

 ÆgfoUikel 4 Celler, hvoraf alene den terminale bli- 

 ver til det egentlige Æg, medens de 3 øvrige fore- 

 stiller Næringsceller og derfor tilsidst ganske absor- 

 beres (se Fig. 14 — 17). De af Ovarierne iidkomne 

 Æg grupperer sig sammen til 2 rvindagtige kage- 

 formige Masser, der bæres under Skallen helt bagtil 

 (se Tab. XVIII, Fig. 1 og 2). Hver Ægmasse inde- 

 holder et stort Antal af Æg, der ved et klæbrigt 

 Stof er heftede sammen. Æggene er omgivne af en 

 simpel, ikke meget fast Kapsel, iiden nogen ioine- 

 faldende Skiilptur. 



Testes (se Tab. XX, Fig. 6) har samme Belig- 

 genhed som Ovarierne og ligner disse ganske hvad 

 Anordningen af FoUiklerne angaar (se Fig. 12). 

 Disse sidste er imidlertid her alle af nogenlunde 

 ens Størrelse og af noget uregelmæssig Form, samt 

 indeholder hver en med den centrale Kanal i For- 

 bindelse staaende Hule, i hvis Vægge de meget smaa 

 oelleagtige Sædelementer udvikle sig. Mundingen 

 for vasa deferentia synes at ligge omtrent paa 

 .samme Sted som Miindingen for Æglederne hos 

 Hunnen. 



Udvikling. — Jeg har desværre ikke selv ha^'t 

 Anledning til at .studere denne Phyllopodes Udvik- 

 ling. Men ifølge G-rubes Undersøgelser synes den i 

 flere væsentlige Punkter at skille sig fra den hos 

 andre Phyllopoder. Larven har et meget eiendom- 

 meligt Udseende, som noget minder om samme hos 

 Cirripedierne. Selv i det tidligste af Grube obser- 

 verede Stadium, som ifølge Lemmernes Beskaffenhed 

 ubetinget er et Naiiplius-Stadium, er nemlig Lege- 

 met dækket oventil af et meget stort fladt Ryg- 

 skjold, og har nedentil et lignende men mindre Skjold, 

 der forestiller Overlæben. Hovedet har en meget 

 eiendommelig Form, idet det gaar ud i 3 korsformigt 



1st pair of antennæ (a '), are ver\' much elongated, 

 and directed obliquely laackwards. The nerves for 

 the oars (a ^) also originate here, starting from the 

 commissures which run Ijackwards from the cerebral 

 gaiiglion. The ventral ganglion chain (PI. XX, fig. 

 19) resembles that in Limnadia. though with the 

 diiference that the nerve .stems are comjjaratively 

 stronger, and lie rather nearer together. The num- 

 ber of ganglionic dilatations is, of course, in accor- 

 dance with the far smaller number of legs, less than 

 in Limnadia. 



The ovaries (see PI. XIX, fig. 1) are of consi- 

 derable size, extending through the whole trunk on 

 each side of the intestine. They present a very 

 much lobed appearance, from the fact that the egg- 

 follicles are grouped botryoidally about the ovarial 

 tubes (se PL XX, fig 13). The oviduct issues from 

 the hind part of each ovary, and seems to open 

 immediately below the before-mentioned tri-lol^ed 

 dorsal lamella; for at that place large masses of 

 mature eggs are often seen accumulated. As in L^ini- 

 nadia, each egg-follicle contains 4 cells, of whicli 

 the terminal one only becomes the true egg, the 

 other 3 representing alimentary cells, and being 

 therefore at last quite absorbed (see figs. 14 — 17). 

 The eggs that have issued from the ovaries congre- 

 gate into 2 roxind, cakelike masses, which are borne 

 beneath the shell at the very back (see PI. XVIII, 

 figs. 1 and 2). Each eggmass contains a large 

 number of eggs, which are fastened together by a 

 glutinous substance. The eggs are surrounded by a 

 simple, not very firm capsule, without any conspi- 

 cuous sculpturing. 



The testes (see PI. XX, fig. 6) have the same 

 position as the ovaries, and resemble them exactly' 

 as regards the arrangement of the follicles (see fig. 

 12). Here, however, the latter are all of about the 

 same size, and of a somewhat irregular shape; each 

 contains a cavity communicating with the central 

 channel, and in whose walls the very small, cellular 

 seminal elements are developed. The opening of 

 the vasa deferentia appears to lie at about the 

 same place as the mouth of the oviducts in the 

 female. 



Development. — I have unfortunately not had 

 an oppftrtunity, personally, of studying the develop- 

 ment of this Phyllopod; but, according to Grube's 

 investigations, it seems, in several essential points, 

 to differ from that of other Phyllopoda. The larva 

 has a very peculiar appearance, somewhat resem- 

 bling that of Cirripedia. Even in the earliest stage 

 observed by G-rube, which, from the condition of 

 the limbs, is unquestionably a nauplius stage, the 

 body is covered above by a very large flat cara- 

 pace, and has a similar, but smaller shield below, 

 which represents the labrum. The head has a very 

 peculiar shape, for it projects in 3 cruciformlj^-placed 



