FAMILY SPHAROMIDA. 101 
endopods thick, of fleshy aspect, with deep, essentially 
transverse folds, the exopods submembranaceous and rather 
pellucid, two-jointed; both rani of both pairs without 
plumose marginal sete; exp. of plp.? has the subapical 
squamiferous protuberance on the lower surface very high. 
Plp. have both rami closely set with long plumose sete, at 
least on the distal margin. Endp. of plp.' at least rather 
broad, scarcely ever half again as long as broad. 
(zs) Sph. eubranchiatze: Plp.tand plp.5 have both rami 
subsimilar, with deep, essentially transverse folds, often of 
fleshy aspect, without plumose marginal sete; exp. of plp.° 
generally distinctly two-jointed, with the subapical squam- 
iferous protuberance on the lower surface very high. Plp.° 
have both rami closely set with long plumose sete at least on 
their distal margin. Endp. of plp.’ at least rather broad, 
scarcely ever half as long again as broad. (Hnd of abdomen 
at least emarginate, generally with a notch or with a slit ter- 
minating-in a foramen.) 
(c) Sph. platybranchiate: Plp.* and plp.® have both 
rami completely without transverse folds, and their exopods 
are unjointed; endp. of plp.* at most with a few short 
terminal plumose sete, exp. of same pair rarely with numerous 
long marginal plumose sete (Tecticeps), inmost genera both 
rami without plumose sete ; both rami of plp.’ without 
plumose marginal sete, and the exp. has the squamiferous 
protuberances slightly in relief, and in rare cases without 
spines or even wanting. Plp.® have sometimes plumose 
marginal sete on both rami as plp.”, sometimes with endp. 
nearly naked or with both both rami naked. Endp. of plp.1 
rarely broad, most frequently narrow. (Hnd of abdomen 
sometimes with a rounded notch, often truncate, rounded, or 
acute.) 
Group A. Spheromine hemibranchiate. 
This group comprises a very large number of forms, but 
in spite of much difference in aspect great uniformity is met 
with in the large majority of more important features. ‘lhe 
