B82 A HISTORY OF RECENT CRUSTACEA 
Nannoniscus, Sars, 1869, has the head produced into a 
frontal process, the pleon consisting of a single piece, sub- 
triangular, apically rounded or truncate. There are no eyes. 
The mandibles have ten spines in the spine-row, the molar 
short and narrow, the ‘palp’ short, three-jointed. The 
operculum of the pleon is short, armed with a tooth; the 
uropods are very short, two-branched, with the inner branch 
the longer, or they are single-branched. The type, Nann- 
oniscus oblongus, Sars, a twelfth of an inch long, was 
taken at depths between 120 and 250 fathoms. It is de- 
scribed as having on the short three-jointed first antennz 
‘a single ovoid olfactory papilla of portentous size” A 
second species, Nannoniscus bicuspis, Sars, has the first 
antennze seven-jointed, the second pair forming on the 
outer side a large triangular process. This species has the 
uropods simple, biarticulate. 
Hugerda, Meinert, 1890, has the last three segments of 
the perzeon longer than the anterior segments, the pleon- 
segments fused into one. The mandibles are without 
molar and ‘palp.’ The maxillipeds have the first three 
joints of the ‘ palp* broad, the last two narrow and small. 
All the limbs of the perzon are long, the first pair more 
slender and smooth than the rest. The opercular plate of 
the pleon is orbicular; the uropods are moderately long, the 
branches single-jointed, the inner the longer. Eugerda 
globiceps is the type. 
Dendrotion, Sars, 1871, has the head divided into two 
ear-like branches, to which the two pairs of antenne are 
attached. ‘The first four segments of the perzeon have each 
a long spine on either side; the three following segments 
are abruptly much narrower. ‘The pleon has all the seg- 
ments fused into one. There are no eyes. The mandibles 
have a conical molar, the ‘ palp’ three-jointed, The first 
limbs of the perzon are shorter than the others, which are 
long and slender. There are no uropods. 
Macrostilis, Sars, 1864, has the first three segments of 
the perzeon so closely united as to give an appearance of 
fusion, the four following segments being very distinct, 
with acute postero-lateral angles. The pleon forms a long 
