250 A HISTORY OF RECENT CRUSTACEA 
nised as a synonym of Nematocarcinus. To this genus 
Spence Bate adds fourteen species from the Challenger 
collection. His Nematocarcinus lanceopes is from the 
Antarctic Sea. The delicacy of the framework in this 
genus sometimes makes fulness of description out of the 
question, as in the case of Nematocarcinus altus, Spence 
Bate, taken from 2,150 fathoms depth, south of the Philip- 
pines. ‘Only one specimen of this species was procured, 
from which all the appendages are wanting, and the 
rostrum is broken near the apex.’ Nematocarcinus undu- 
latipes, Spence Bate, shown on Plate X., appears to be the 
commonest species. 
Stochasmus, Spence Bate, 1888, means ‘a conjecture,’ 
the name alluding to the inconvenient circumstance that 
‘unfortunately only one very imperfect specimen was ob- 
tained ; all the pereiopoda are gone, and its relation to 
Nematocarcinus can therefore only be conjectured.’ It 
differs from that genus in having a ‘ dactylos’ or seventh 
joint attached to the extremity of the third maxillipeds ; 
in other respects it is in close agreement with it. It is 
said to differ from Nematocarcinus cursor, A. Milne- 
Edwards, only in the number and character of the spines 
on the rostrum. 
Family 8.—Stylodactylide. 
The second maxillipeds have a two-branched termina- 
tion, and the first two pairs of trunk-legs have the arms 
of the chela, the so-called thumb and finger, long, slender, 
and feeble. ‘There is but one genus in the family. 
Stylodactylus, Milne-Edwards, 1883. ‘The name evi- 
dently alludes to the very peculiar stiliform fingers in the 
chelipeds, and the spelling follows the old-standing confu- 
sion between the Greek word crdXos, a pillar, and the 
quite distinct Latin word stilus, a pointed instrument. 
The genus occurs both in the Pacific and the Atlantic. 
The rostrum is a very long and conspicuous feature, in 
Stylodactylus serratus, A. Milne-Edwards, having forty 
spines on the upper and twenty on the lower margin, and 
being just upon an inch long in a specimen of which the 
entire length was two inches and three-fifths, 
