752 



THE VOYAGE OF H.M.S. CHALLENGER. 



The pleon is smooth to the fourth somite, which dorsally projects to a small tooth in 

 the median line, and a similar tooth is also present on the fifth. 



The ophthalmopoda are short and pyriform. 



The first pair of antennas has the peduncle subequal in length with the rostrum, and 

 the scaphocerite reaches considerably beyond it. 



Length, entire, 



of carapace, * 



of rostrum, 



of pleon, . 



of third somite of pleon, 



of sixth somite of pleon, 



of telson, . 



41 mm. (L6 in.). 



14 



4 



27 



4 



6-5 



8-5 



Habitat— Station 107, August 26, 1873 ; lat. 1° 22' N., long. 26° 36' W.; Atlantic, 

 south-west of Sierra Leone; depth, 1500 fathoms; bottom, Globigerina ooze; bottom 

 temperature, 37°'9. Two specimens. Trawled. 



The carapace is slightly carinated and anteriorly produced to a rostrum that is 

 scarcely one-fourth the length of the carapace, and is armed on the upper surface with 

 nine small teeth ; the orbit is deeply excavate, and from the middle a ridge runs obliquely 

 to the hepatic sulcus, whence it passes to the posterior margin. 



The pleon has the first three somites dorsally smooth ; the three succeeding somites 

 have a minute tooth in the median line, and the telson (fig. 6z) is long, tapering, and 

 grooved in the median line, the ridges of the groove being furnished with small spinules. 



The ophthalmopoda (fig. 6a) are short, about half the length of the rostrum, 

 pyriform in shape, and furnished with an ocellus that is only partially detached from the 

 ophthalmus ; on the outer side of the ophthalmopod, beyond the margin of the 

 ophthalmus, is a small but prominent process. 



The first pair of antennae has the peduncle reaching beyond the apex of the rostrum, 

 and the second pair has the scaphocerite longer than the peduncle of the first. 



The pereiopoda are all broken off. 



The first pair of pleopoda (fig. 6p) is biramose, having the inner branch membranous. 



The sixth pair has the branches slightly unequal, the inner being subequal with the 

 telson and the outer longer. 



Observations. — In the same bottle was a second specimen (fig. 6) which was found 

 associated with it, and which differs from the preceding description in having ten teeth 

 on the upper margin of the rostrum, and in having a small tooth on the lower margin, 

 just beyond the distal extremity of the ophthalmopoda. In this specimen the first pair of 

 pereiopoda is preserved and shows that it is a feeble and slender chelate organ. The two 

 specimens in all other points correspond very closely ; the latter is rather larger and 



