6 
disse Formers Organisation forevrigt kun er yderst plate; and although the organization of those forms 
ufuldsteendigt kjendt (endnu har man saaledes ingen- 
somhelst Kjendskab til Lemmernes Beskaffenhed hos 
disse Former), har Packard nylig indbefattet dem 
under samme Gruppe (Orden) som Nebalia. Uagtet 
jeg for flere af disse fossile Formers Vedkommende 
anser det for meget tvivlsomt, hvorvidt de lader sig 
henfere til denne Gruppe, har jeg dog forsegt at 
give den ovenstaaende Diagnose af Underordenen en 
saavidt rummelig Character, at de nevnte fossile 
Former til Nod lader sig indbefatte under samme. 
De faa hidtil kjendte levende Former horer utvivl- 
somt alle til en og samme Familie, der passende vil 
kunne benevnes efter den forst opstillede og derfor 
typiske Slegt. 
is, otherwise, extremely imperfectly known (we have, 
for instance, not the slightest knowledge of the 
nature of the appendages in those forms), Packard 
has lately included them in the same group (order), 
as Nebalia. Although I, in regard to several of 
those fossil forms, consider it very doubtful whether 
they can be assigned to that group, I have yet 
endeavoured to give the above diagnosis of the 
sub-order such a broad character, that the fossil 
forms referred to, may, if necessary, be included in 
it.. The few hitherto known living forms all belong, 
undoubtedly, to one and the same family, which may 
suitably be named after the first established and 
therefore typical genus. 
Fam. Nebaliide. 
Character. — Legemet mere eller mindre for- 
lenget, successivt afsmalnende bagtil, uden skarpt 
markeret Begrendsning mellem For- og Bagkrop. 
Rygskjoldet. kun helt fortil umiddelbart forbundet 
med Legemet, sammentrykt, tveklappet, Valvlerne be- 
veegelige og sammenholdte ved en tydelig Adductor- 
muskel; Pandepladen tungedannet, forbundet med 
Rygskjoldet ved et tydeligt Led. Truncus lost 
overdekket af Rygskjoldet og delt i8 fuldstendige 
Segmenter af ens Udvikling. Bagkroppen bestaaende 
af 2 mere eller mindre tydeligt begreendsede A fsnit, 
hvert sammensat af 4 Segmenter. Ginene festede 
tet sammen under Basis af Pandepladen og diver- 
gerende til hver Side. Begge Par Folere kraftigt 
udviklede, subpediforme, Skaftet dobbelt kneeboiet, 
Svoben mangeleddet; de ovre med et lamelleformigt 
berstebesat Vedheng ved Enden af Skaftet. Kind- 
bakkerne forholdsvis, smaa, men med vel udviklet 
Palpe; Tyggedelen hovedsageligt representeret af 
Molarprocessen. iste Par Kjever med 2 indadret- 
tede Tyggelappe og en lang, borsteformig, bagudrettet 
Palpe; 2det Par lamellere, med mere eller mindre 
udviklet Palpe og Exognath. 8 Par mere eller min- 
dre udpreeget bladdannede, respiratoriske Lemmer 
’ tilstede paa Forkroppen, bestaaende af Endo-, Exo- 
og Epipodit, den forste mere eller mindre forlenget, 
med Inderkanten teet borstebesat, men uden tyde- 
lige Enditer eller Flige De 4 forreste Par Bag- 
kropslemmer omformede til kraftige, tvegrenede 
Svemmefodder; de 2 folgende Par rudimentere. De 
2 sidste Segmenter uden Buglemmer. Halegrenene 
simple, lineere eller lamellere, tet borstebesatte 
Fam. Nebaliide. 
Characters. — Body more or less prolonged, 
tapering backwards gradually, without sharply 
defined demarcation between the anterior and pos- 
terior divisions. Carapace attached, only quite 
in front, immediately to the body, compressed, bi- 
lobate, the valves mobile and kept together by 
a distinct adductor muscle. Frontal plate lingui- 
form, attached to the carapace by a distinct joint. 
Truncus loosely covered by the carapace and 
divided into 8 perfect segments of uniform develop- 
ment. The posterior division of the body consisting - 
of 2 more or less distinctly defined sections, each 
composed of 4 segments. Eyes secured close together 
below the base of the frontal plate, and divergent 
to each side. Both pairs of antenne powerfully 
developed, subpediform, peduncle double-genicul- 
ated, flagellum multiarticulate; the superior ones 
with a lamelliform setous appendage at the ex- 
tremity of the peduncle. Mandibles relatively 
small, but with well developed palp; the mastica- 
tory part represented chiefly by the molar expan- 
sion. First pair of maxille with two inwardly dir- 
ected masticatory lobes and a long setaceous palp 
directed backwards; 2nd pair lamellar with more or 
less developed palp and exognath. Eight pairs of 
more or less prominently foliaceous respiratory appen- 
dages present on the anterior division of the body, 
consisting of endo-, exo-, and epipodite; the first 
more or less prolonged, with the inner edge closely 
beset with bristles but without distinct endites or 
laps. The 4 foremost pairs of appendages of the 
posterior division of the body transformed into 
