250 A HISTORY OF RECENT CRUSTACEA 



nised as a synonym of Nematoaarcinwt. To this genus 

 Spence Bate adds foarteen species from the Challenger 

 collection. His Nematoca/rdnus 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 Nematoca/rcinus alius, 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.' Nemaiocarcinus undw- 

 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 

 Nematoca/rcinus 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 Nematoca/rcinus cursor, A. Milne- 

 Edwards, only in the number and character of the spines 

 on the rostrum. 



Family 8. — Stylodactylidce. 



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. 



Stylodact/ylus, 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 crriiXos, 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. 



