102 H. J. HANSEN. 
proximal joints of the antennz never protrude with free ex- 
pansions in front of the head; they are fitted in oblique 
excavations. In the mouth-parts only the development of 
the incisive process of the mandibles and the “ palp” of the 
maxillipeds show noteworthy generic differences, excepting 
the metamorphosis in the females in half of the forms. The 
thoracic legs are all simple, without sexual difference. The 
pleopods in the different genera are so uniform that scarcely 
more than the exopods of plp.® and plp.® present generic 
differences. The exopod of the uropods is always present, but 
sometimes exceedingly small. The brood is developed in 
internal pouches. The body is never strongly depressed, the 
faculty of rolling excellently developed, the lateral margin 
of thorax not continuous. 
The group is divided into two sections about equal in 
number of genera. — 
(a) Sphe romini.—End of abdomen in the female without 
notch, rounded or somewhat produced and more or less acute ; 
in the male generally as in the female, in some forms the end 
much produced with a pair of lateral notches, so that the 
mesial part is shaped as a process narrowed at the base.! 
Mouth-parts similar in both sexes. 
(a) Maxillipeds with the lobes from fourth, fifth, and sixth 
joints low or rudimentary. Three anterior pairs of thoracic 
legs closely set with exceedingly long stiff plumose setze on the 
outer margin of third and fourth joints. Exp. of plp.2 un- 
jointed. Marsupial lamelle overlap each other at the mesial 
line (they are unknown in H emisphezroma, which probably 
does not differ from Spheeroma in this respect). 
+ Mandibles normal, the cutting process not elongate, its 
1 In a species from Simon’s Bay, at Cape, closely allied to or identical with 
Spheroma scabriculum (Hell.), the end of abdomen in the female is as in 
Exospheroma, while in the male a notch, as in the male Dynamenella 
(compare the diagnosis below) is observed; the specimen described by Heller 
is evidently a male. The female of the species seen by me cannot be separated 
from Exospheroma, while the structure in the male alluded to is very 
curious. For various reasons I omit this form from the conspectus, hoping 
to obtain more material of allied species. 
