125 



De 2 folgeiule (9de og 10de"i Par (se Pig. 3) 

 raaugler, ligesom det sde, ganske Epipodit, og ud- 

 mærker sig desiiden ved det eiendommelige ITdseende 

 af Exopoditeiis dorsale Lap. Denne er nemlig paa 

 begge disse Par omformet til en eylindri.sk Streng, 

 der er kageformigt oml)oiet i Enden og her forsj'net 

 med en tæt Ciliering. Det er aabenbart, at disse 

 4 Appendices (se ogsaa Tab. XIX, Fig. .1, Fig. 9, fh) 

 er bestemt til. i Forening med de ovenfor omtalte, 

 fra Ej'gsiden af de 2 bagerste Truncus-Segmenter 

 udgaaende, bladformige Plader (1), at stotte de 2 

 kageformige Ægmasser, der bæres nnder Skallens 

 bagre Del. 



De 2 sidste Fodpar (Tab. XX, Fig. 4, 5) er meget 

 smaa, navnlig det bagerste (12te) Par, og mangler 

 baade Epipodit og den dorsale Lap af Exopoditen. 

 Forovrigt ligner de i Structnr de 2 foregaaende Par, 

 og liar, som disse, alle Enditer. ligesom ogsaa Coxal- 

 lappen, tvdeligt ndviklede, skjondt meget tæt sam- 

 mentrængte. Den ventrale Lap af Exopoditen er 

 [)aa sidste Par (Fig. 5) reduceret til et fra den ydre 

 Side af Endopoditen udgaaende meget lidet, med 5 

 Bor.ster for.s\-net Appendix. 



Beskrivelse af Hannen. 



Hannerne er gjennemgaaende noget mindre end 

 Hunnerne, idet Skallen neppe opnaar en Længde af 

 4 mm. Den er ogsaa (se Tab. XVIIL Fig. 3) noget 

 mere nregelmæssig af Form, med Forenden mere 

 tvært afknttet, og de nedre Kanter dannende fortil 

 en meget stærk. næsten vinkelformig Krumning. 

 Forovrigt ligner Skallen samme hos Hunnen og er 

 fuldkommen ligesaa stærkt buget som hos denne. 



Det i Skallen indesluttede Dyr (se Tab. XX, 

 Fig. (i) viser dere characteristiske Eiendommelig- 

 heder, hvorved det strax skiller sig fra samme hos 

 Hunnen. Hovedet er saaledes betydelig kortere og 

 Rostrum af en meget afvigende Form. Seet fra 

 Siden (se Tab. XVIII, Fig. 3, Tab. XX, Fig. (3) er 

 det næ.sten jevnt bredt og har Enden, ikke som hos 

 Hunnen udtrukket til en skarp Spids, men stumpt 

 afrnndet. Forfra seet (Tab. XVIII, Fig. 5) viser det 

 sig tvært afkuttet i Enden, idet den mediane Spids 

 ganske mangler, medens de laterale Fortsatser, hvori 

 Hovedets Sidekjole gaar ud, er betydelig mere ud- 

 staaende end hos Hunnen og næsten retvinklede. 

 Af de eiendommelige tretligede Blade, der hos Hun- 

 nen udgaar fra Rygsiden af Truncus bagtil, er der 

 intetsomhelst Spor at opdage (se Tab. XX, Fig. (3). 



Haledelen (Fig. 10) har ogsaa en noget forskjel- 

 lig Form, idet de 2 Endeflige er betydelig stærkere 

 forlængede end hos Hunnen og tættere cilierede. 



The 2 succeeding (9th and lOth) pairs (sea fig. 3) 

 are, like the 8th, marked by a total absence of an 

 epipodite. and are also distinguished by the peculiar 

 appearance of tlie dorsal lobe of the exopodite. In 

 both these pairs, this lobe is converted into a 

 cylindrical cord, whit'h is bent down at the end like 

 a- hook, and thickly ciliated. It is evident that 

 these 4 appendages (see also PI. XIX, fig. 1, fig. 9, fh) 

 are intended, in conjunction with the above-men- 

 tioned leaf-like lamellæ (1) issuing from the dorsal 

 side of the 2 hindmost segments of the trunk, to 

 support the 2 cakedike masses of eggs, which are 

 borne beneath the ]iosterior part of the shell. 



The last 2 pairs of legs (PL XX, figs. 4, o) are 

 very small, especially the hindmost (12th) pair, and 

 are without both ejiipodite and dorsal lobe of the 

 exopodite. In other respects they resemble the 2 

 preceding pairs in structure, and have, like them, 

 all the endites, as well as the coxal lobe, di.stinctly 

 developed, although very closely crowded together. 

 The ventral lobe of the exopodite in the last pair 

 (fig. 5) is reduced 'to a very small appendage pro- 

 jecting from tlie outer side of the endopodite, and 

 furnished with ii bristles. 



Description of tlie 3Iale. 



The males, on an average, are rather smaller 

 than the females, as the .shell scarcely attains a 

 length of 4 mm. It is also (see PI. XVIII, fig. 3) 

 rather more irregular in shape, witli tlie anterior 

 end more abruptly truncated, and the lower edges 

 fVirming in front a \exy sharp, almost angular curve. 

 In other respects the shell resembles that of the 

 female, and is quite as much vaulted. 



The animal enclosed iji the shell (see PI. XX, 

 fig. (3) exhibits several characteristic peculiaritie.s, 

 thereby being immediately distinguished from the 

 female. The head is consideralily shorter, and the 

 rostrum of a very different shape. Seen from the 

 side (see PI. XVIII, fig. 3; PI. XX, fig. 6), it is of 

 almost even breadth, the end not being drawn out, 

 as in the female, to a sharp point, but being bluntly 

 rounded. Seen from the front (PI. XVIII, fig. 5), 

 it appears abruptly truncated at the end, the median 

 point being altogether absent, while the lateral pro- 

 jections into which the side keels of the head are 

 jiroduced are considerably more prominent than in 

 the female, and almost rectangular. There is no 

 trace whatever to l)e discovered of the peculiar tri- 

 lobed lamellæ, which, in the female, issue from the 

 dorsal surface of the trunk behind (see PI. XX, 

 rig, (J). 



The cauilal part (fig. 10) is also of a somewhat 

 different shape, the 2 terminal lobes being consider- 

 ably more elongated than in the female, and more 

 tliicklv ciliated. 



