1330 THE VOYAGE OF H.M.S. CHALLENGER. 



Cystisoma spinosum (Fabricius). Specimens C, CC. 



Specimen C. — Length, one inch and eight-tenths ; antennae seven-tenths of an inch, 

 a little longer than those of the very much larger specimen A, and placed much nearer to 

 one another than in that specimen ; third perseopods just under an inch and a half, the 

 first joint half an inch, the following two together nine-thirtieths, the fourth and fifth 

 each ten-thirtieths of an inch ; the fourth perreopods just under an inch in length, the 

 fourth and fifth joints equal ; no trace could be perceived of the small branchial vesicles 

 related to the second gnathopods and first perseopods ; the uropods similar in their 

 proportions to those of the specimen from Station 224. 



Specimen CC. — Length, one inch and eight-tenths ; the antennae not especially near 

 together as in the companion specimen ; the small branchial vesicles related respectively 

 to the second gnathopods and the first perseopods, and the three large pairs, similar to 

 those described for specimen A. 



Locality. — Station 101, August 19, 1873; off Sierra Leone; lat. 5° 48' N., long. 

 14° 20' W. ; depth, 2500 fathoms; bottom, blue mud; bottom temperature, 36° - 4 ; 

 surface temperature, 7 9° "2. Two specimens. Trawled. 



Remarks. — Sir "Wyville Thomson (see Note, p. 471), in noticing specimen B, says, 

 " We have since taken several specimens at different stations in the Atlantic," and " as a 

 small male was in one case captured in the towing-net," he infers that the animals of this 

 genus occasionally come to the surface. As no especial notice is taken of the occurrence 

 of Cystisoma at the remarkable depth of 2500 fathoms, some doubt may have been felt 

 whether the two specimens of Station 101 actually came from that depth. Indeed, as 

 Mr. Murray has frequently pointed out, although the dredge or trawl may have been 

 down to a depth of 2500 fathoms, there is no certainty that many of the animals captured 

 came from that depth, as they may have been taken at any depth between the bottom 

 and surface. Since only four specimens of the genus Cystisoma seem to have been taken 

 in the Atlantic, I am inclined to believe that the " several specimens " mentioned may 

 have included some belonging in reality to the genus Lanceola. 



Cystisoma spinosum (Fabricius) (PI. CLVL). Specimen D. 



Head with twelve teeth on each lateral margin. 



Upper Antennae. — The distal part broken off, so that the full length could not be 

 ascertained, the remaining portion rather thick, tapering, one-fifth of an inch long. 

 Of the spines on either side of the central line on the under side of the head, there 

 are only two pairs, the upper pair (which possibly represent the Lower Antennas) being 



