FAMILY SPHHROMIDA. 105 
both sexes. End of abdomen produced, with a deep groove 
below ; the mesial lobe large, sub-triangular, its lateral walls 
bent downwards, so that the longitudinal groove is continued 
on the lower side of the process, while the two teeth—in 
Cymodoce constituting the lateral limits of the notch—are 
situated on the lower margins of abdomen at the base of 
the process, and quite invisible from above.) 
(9) Bregmocerella (Hasw.). 
The genus Cassidinella (Whitelegge), which is unknown 
to me, belongs probably to this section; in the following 
chapter it is mentioned in the treatment of the genus 
Cymodoce, and discussed as the tenth genus of the hemi- 
branchiate Spheromine. 
Group B. Spheromine eubranchiate. 
This group comprises as many genera as group A, but the 
number of species is much less. Mouth-parts—excepting the 
metamorphosis in the females of several genera—and pleopods 
are very uniform in all points of importance; the end of 
abdomen is at least a little emarginate (Cassidinopsis (n. 
gen.) ), but otherwise with a real notch or a tube or foramen 
connected by a slit with the end itself. The basal joints of 
the antennule afford sometimes a fine generic character. 
The thoracic legs are always simple, the two anterior pairs 
without prehensile hands, and in no case has any special 
equipment with natatory sete or any sexual difference 
been observed; the strong thickening of some pairs in 
Amphoroidea is the most noteworthy feature discovered. 
In some genera, containing animals of moderate or con- 
siderable size, the rami of plp* and plp.’ are thick, of fleshy 
aspect, while they are thinner in small forms, but in all 
species the folds are well developed. An articulation on exp. 
of plp.* could generally not be perceived, but it is very dis- 
tinct in Scutuloidea; exp. of plp.® is generally divided 
rather near the end, but this articulation is not always easily 
observed; this exp. has three bosses, two of which on the 
