2l6 



DISCOVERY REPORTS 



As in the Scotia specimens the dorsal keel on pleon segments 1-3 is scarcely marked 

 in the no. 3 specimens, though it is in both specimens of no. 1. The first side-plate is 

 not as deep as its segment and is in fact slightly smaller than the 2nd. The telson is not 

 longer than the 6th pleon segment. It is not so in Pfeffer's figure, and it seems possible 

 that Pfeffer by a slip wrote "urn ein Drittel liinger" (p. 123) instead of " . . .kiirzer". 



The antennae are proportionately not so stout as in Pfeffer's figure. In gnathopod 2 

 the 6th joint is not as long as the 2nd ; in the middle of the palm there is a short stout 

 spine, followed by a step, the defining angle bearing a long slender spine as described by 

 Pfeffer. The step in the palm is scarcely indi- 

 cated in immature specimens of 23-26 mm. 

 length. The 2nd joints of peraeopods 3-5 

 are quite different in lot no. 3, being much 

 more elongate, and having the front and hind 

 margins nearly straight and parallel, though 

 converging slightly distally; the greatest 

 breadth goes at least twice into the length 

 in peraeopod 3, and 2^-3 times in peraeopod 



Fig. 133. Paraceradocusmiersi{?ir.). Gnathopod 2. 



5. These three peraeopods are altogether 

 longer than in Pfeffer's figure. 



Comparing, however, the <$ of no. 1 (42 mm.) with a 46 mm. $ of no. 3, we find that 

 peraeopods 3-5 are all much shorter proportionately, peraeopod 5 of the S only 

 equalling peraeopod 3 of the 9. The 2nd joints also are stouter, especially proximally. 

 These specimens therefore approximate to the typical form. 



The peduncle of uropod 1 has a well-marked tooth bearing a spine about midway on 

 lower margin; Pfeffer's figure shows a spine nearer the base. The rami of uropod 3 are 

 represented in Pfeffer's figure as much too broad, even for Pfeffer's description (here 

 again a slip occurs: "Breite beim <$ noch nicht \ der Breite", the last word should 

 obviously be " Lange "). 



Lastly, the eye is not dark as in Pfeffer's figure, but shows through the cuticle as a 

 whitish patch. The cuticle over the eyes is perfectly smooth, not in the least convex, and 

 in no way different from the cuticle over the rest of the head. When dissected out, the 

 eye is found to consist of a mass of whitish pigment-tissue with irregularly scattered, 

 and not too closely aggregated, crystal-cones. The optic nerve is stout and apparently 

 well developed. I have not had the time necessary for sectioning this eye, but the 

 material seems to be in good condition for histological investigation, and the size of the 

 animal would make it very convenient for study. 



The no. 3 lot are far and away the largest yet recorded; they also come from much 

 deeper water. 



Distribution. South Georgia; South Orkneys; Graham Land; South Shetlands. 

 Low tide to 70 m. 



