250 A HISTOEY OF EECENT CRUSTACEA 



nised as a synonym of Nematocarcinu^. 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 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 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. — 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. 



Stylodactijlus, 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 cttvXos, 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. 



