350 THE VOYAGE OF H.M.S. CHALLENGES. 



appendages. Synaphipod reaching beyond the extremity of the peduncle of the second 

 pair of antennae. 



The rest of the animal is so damaged that it is difficult to give a specific description. 



Habitat.— Station 146, December 29, 1873; lat. 46° 46' S., long. 45° 31' E.; near 

 Marion Island; depth, 1375 fathoms; bottom, Globigerina ooze; bottom temperature, 

 35° "6. Four specimens, females. Trawled. 



Station 159, March 10, 1874; lat. 47° 25' S., long. 130° 22' E.; south of Australia ; 

 depth, 2150 fathoms; bottom, Globigerina ooze; bottom temperature, 34° - 5. One 

 specimen, female. Trawled. 



This species, so far as it can be determined from the damaged specimens in the 

 Challenger collection, is very like Sergestes japonicus, but it may be very readily dis- 

 criminated by the dark brown colour of the hairs attached to the margins of the 

 synaphipod and other oral appendages. 



The nervous system in one specimen being in a tolerably good state of preservation, 

 I was enabled to lay it bare in its entire length from the cephalon to the extremity 

 of the pereion. 



The cephalic lobes are very large and apparently divided into lobules, corresponding 

 to the branches that are given off. The ophthalmic branch is very small and thread- 

 like, while that which supplies the first pair of antennae is very large, strong, and 

 originates in a special ganglion in front of, but belonging to, the cerebral mass, while 

 behind, from the largest mass, two stout nerves, independent of each other, lead to the 

 second pair of antennae, one apparently going to the green gland, and the other to the 

 antennae or antennal muscles, which are exceptionally strong. The oral branches of the 

 nerves are small and arise from the oesophageal loop, while all the limbs attached to the 

 pereion are supplied from the ganglionic masses on the ventral surface in the following 

 manner. The anterior two ganglia supply the gnathopoda. The three next supply the 

 corresponding pairs of pereiopoda, of which the posterior is connected with, and supports, 

 the oviducts, and is a slightly larger ganglion than the preceding ; the central cord at 

 this point divides into two, and reunites at the next ganglion, which sends off two 

 branches to the penultimate and two to the ultimate pairs of pereiopoda, after which the 

 central cord becomes single as it traverses the median ventral line of the pleon ; conse- 

 quently there is no ganglion corresponding with the posterior pair of pereiopoda. 



Sergestes, Milne-Edwards. 



Sergestes, Milne Edwards, Ann. d. Sci. Nat., ser. 2, voL xis. p. 346, 1830. 



Body long and slender. Structure submembranous. Carapace scarcely produced to 

 a rostrum anteriorly. Ophthalmopod single-jointed. 



