CRUSTACEA FROM THE 'CHALLENGER' EXPEDITION. 37 



covered by the carapace, one branch turned inside between the legs and in free commu- 

 nication with the water. "Well developed pleopods. Caudal appendages jointed. 



1. Gn. gigas, n. sp. 



Scale of the second antennae with five spines, not jointed ; short spines at the lateral 

 angles of the dorsal shield, no spine in the midst of the upper posterior margin. 

 Length 142 millims. Colour red. 



2. Gn. zoea, n. sp. 



Scale of the second antennae with only one spine, jointed ; dorsal shield with a sharp 

 spine in the midst of its upper posterior margin, lateral posterior angles rounded. 

 Length 59 millims. Colour red. 



3. Gn. gracilis, n. sp. 



Scale of the second antennae with one spine ; dorsal shield with a spine in the middle 

 of its upper posterior margin, and two spines in its anterior as well as in its posterior 

 lateral angles. 



Length 41 millims. Colour red. 



2. On Chalaraspis, the Type of a new Schizopod Family. (Plate VIII.) 

 This little Crustacean is the commonest Schizopod of the deep-sea fauna, and seems to 

 enjoy a very wide bathymetrical and geographical distribution ; for we got it from depths 

 of 350-2500 fathoms, off the west coast of Africa, as well as off the east coast of South 

 America, down to the 35th degree of southern latitude. Whenever in the mid- Atlantic 

 true deep-sea animals came up in the dredge or the trawl, I was sure to get at least a 

 fragment of this Crustacean. Unfortunately most of the specimens were spoiled ; only a 

 few males and females were in a good state of preservation. The animal is so soft that it 

 does not stand the long passage of the trawl through the water ; and even if it is not 

 broken to pieces, its carapace is usually overturned. On two occasions, however, I got 

 specimens which are quite intact ; and these, as well as the many fragments, furnished 

 ample opportunity of studying this genus in all its details. 



The females of this shrimp have a length of 35 millims., the carapace having from 

 above a length of 8 millims. and laterally of 12 millims. The males are 37 millims. in 

 length, but somewhat more slender than the females ; their dorsal shield has the same 

 length from above as that of the females, but is laterally somewhat shorter (ll-i millims.). 

 The carapace is very soft, especially in the males, and in connexion with only the first 

 segments of the pereion. It has a very short, rounded rostrum (fig. 1 a), and on the 

 frontal border a pair of short spines underneath the eyes. The lateral anterior border is 

 rounded in the female, and somewhat angular in the male. The posterior border of the 

 carapace shows a deep excision, especially in the male, so that its rounded lateral borders 

 cover a great deal more of the pereion-segments than the upper margin (fig. 1). The 

 carapace is divided by a longitudinal ridge and two transverse sulci into several regions, 

 which in old females are very well marked ; in the males, however, they are not always 

 plainly visible. 



