125 



De 2 folgende (9de. ng lOde') Par (>je Fig. 3) 

 mangler, ligesom det sde. ganske Ejnpodit, og ud- 

 raærker sig desuden ved det eiendommelige Udseende 

 af Exopoditens dorsale Lap. Denne er nemlig paa 

 hegge disse Par omformet til en cylindrisk Streng, 

 der er hageformigt omboiet i Enden og her forsynet 

 med en tæt Ciliering. Det er aabenbart, at disse 

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

 er bestemt til. i Forening med de ovenfor omtalte, 

 fra Rygsiden af de 2 bagerste Truncus-Segmenter 

 udgaaende, bladformige Plader (1), at .støtte de 2 

 kageformige Ægmasser, der bæres under Skallens 

 l)agre Del. 



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

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

 baade Epipodit og den dorsale Lap af Exopoditen. 

 Forovrigt ligner de i Structur de 2 foregaaende Par, 

 og har, som disse, alle Enditer, ligesom ogsaa Coxal- 

 lappen, tydeligt udviklede, skjondt meget tæt sam- 

 mentrængte. Den ventrale Lap af Exopoditen er 

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

 Side af Endopoditen ndgaaende meget lidet, med 5 

 I^orster forsynet 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. XVIIT, Fig. ii) noget 

 mere uregelmæssig af Form, med Forenden mere 

 tvært afkuttet, og de nedre Kanter dannende fortil 

 en meget stærk, næsten vinkelformig Krumning. 

 Forovrigt ligner Skallen samme hos Huniien og er 

 fuldkommen ligesaa stærkt buget som hos denne. 



Det i Skallen indesluttede Dyr (se Tab. XX, 

 Fig. <i) viser tiere characteristi.ske Eiendommelig- 

 heder, hvorved det strax skiller sig fra samme hos 

 Hunnen. Hovedet er saaledes betydelig kortere og 

 Ivostrum af en meget afvigende Form. Seet fra 

 Siden (se Tab. XVIII, Fig. 3, Tali. XX, Fig. 6) er 

 det næsten jevnt l)rfdt og har Elnden, ikke som hos 

 Hunnen udti'ukket til en .skar|) Spids, men stumpt 

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

 sig tvært afkuttet i Enden, idet den mediane Spids 

 ganske mangler, meilens de laterale Fortsatser, hv(U-i 

 llovi'dets Sidekjole guar ud, er betydelig mere ud- 

 staaende end hos Hunnen og næsten ivtvinklede. 

 Af de eiendonnnelige trctligede Blade, der hos Hun- 

 nen udgaar fra Rygsiden af Truueus bagtil, er der 

 intetsomhelst Spor at o]idage (se Tab. XX, Fig. G). 



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

 lig Fiirni, idi't de 2 Rndotlige er betydelig stærkere 

 forlængede end hos Hunnen og tættere cilierede. 



The 2 succeeding (9th and lOth) i)airs (see fig. 3) 

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

 epi])oditc, and are also distinguished by the peculiar 

 a])pearance of the dorsal lobe of the exo])odite. In 

 both these pairs, this lobe is converted into a 

 <'ylindrical cord, which is bent down at the end like 

 a hook, and thickly ciliated. It is evident that 

 these 4 ajipendages (sec also 1*1. XIX, fig. 1, fig. 9, /"/>) 

 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 cake-like masses of eggs, which are 

 borne beneath the posterior part of the .shell. 



The last 2 pairs of legs (PI. XX, figs. 4, 5) are 

 very small, es])ecially the hindmo.st (12th) pair, and 

 are without both epipodite 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 hilif, distinctly 

 developed, although very closely crowded together. 

 The ventral lobe of the exopodite in the last ])air 

 (fig. 5) is reduced jto a very .small apjiendage pro- 

 jecting from the outfi' side of the endo]M>dite, and 

 furnished with 5 bristles. 



Description of the 3Iale. 



The males, nn an average, are rather smaller 

 than the females, as the shell scarcely attains a 

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

 rather more irregular in shape, with the anterior 

 end more abruptly truncated, and the lower edges 

 forming in front a very sharp, almost angular curve. 

 In other respects the shell resembles that of the 

 female, and is (piite as much vaulted. 



The animal enclosed in the shell (see i'l. XX, 

 rig. I!) exhibits several characteristic peculiarities, 

 thereby being immediately distinguished from the 

 female. Tlie head is considerabh- shorter, and the 

 rostrum (if a very different shape. Seen from the 

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

 almost even bi'eadth, the end not being drawn out, 

 as in the female, to a sharp point, but l)eing blunth' 

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

 it ajijieai's abrujitly truncated at the end, the median 

 point being altogether absent, while the lateral pro- 

 jections into wliich the side keels of tiie head are 

 ])ro(luced arc considerably more ])rominent 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 tlie trunk behind (see PI. XX, 

 fig. C). 



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

 different shape, the 2 terminal lobes being coiisider- 

 ably more elongated than in the female, ami more 

 tliicklv ciliated. 



