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



tuberculated dorsally and has a long spine on cither side, somewhal curved backwards 

 and projecting at right angles, which is placed on a line with the lateral margin of the 

 caudal shield. Ventrally these segments are furnished with spines arranged in the 

 following fashion: the last thoracic segment has a single median spine of considerable 

 length; the first abdominal segment has anteriorly a pair of short spines closely 

 approximated, and on either side of the median line ; posteriorly and just in front of the 

 uropoda, the anterior ends of which abut against this segment, are a row of spines, of 

 which two, one on either side, are particularly long, and have been referred to above. 



The caudal shield has a dorsal keel which is prolonged posteriorly into a longish 

 curved spine ; the whole of its dorsal surface is covered with numerous tubercles pointed 

 at their extremity. The lateral margin of the caudal shield forms a flattened sen-ate 

 ridge, which terminates posteriorly in a flattened triangular spine on either side. 



The proximal joints of the antennas, as well as of the thoracic limbs (figs. 3-4), are 

 furnished with numerous slender short spines ; there are a pair of such spines, one upon each 

 antennule, on the first joint; they are particularly abundant on the basal joint of the 

 anterior thoracic limbs ; the three posterior pairs of thoracic appendages have one or two 

 such spines. 



The uropoda are beset with numerous small spiny tubercles, and each has a longish 

 curved spine placed nearly vertically below the long spines on the posterior free 

 abdominal seoruent. 



Station 149b, January 17, 1874, off Eoyal Sound, Kerguelen ; hit, 49° 28' S., long. 

 70° 30' E. ; depth, 25 fathoms ; volcanic mud. 



Station 149h, January 29, 1874, off Cumberland Bay, Kerguelen; lat. 48° 45' S., 

 long. 69° 14' E. ; depth, 127 fathoms; volcanic mud. 



Arcturus oculatus, F. E. Beddard (PL XXV. figs. 1-4). 



Arcturus oculatus, F. E. Beddard, Proc. Zool. Soc. Lond., 1886, pt. i. p. 112. 



Five specimens of this small species were dredged in shallow water, off Melbourne, 

 South Australia. 



The largest measures no more than 6 mm. in length. 



The most remarkable point about this species, and one which serves at a glance to 

 distinguish it from any other recorded species of the genus, is the elevation of the eyes 

 on stalks ; these are, however, merely prolongations of the body-wall, and are not 

 articulated with it by a joint as in the Decapoda. Nevertheless the approximation to the 

 Decapoda in this respect is of some little interest, and is perfectly unique within the 

 genus. In other respects the present species exhibits no marked divergences from other 

 Arcturi, and I have not thought it necessary to separate it generically simply on account 

 of the peculiarities in the peduncles of the eyes. 



