METOPIDAE I09 



generic character. It is far more satisfactory than the presence or absence of an 

 accessory flagellum in antenna i for separating this genus from Metopoides. 

 The following key to the austral species may be useful. 



I. Postero-inferior angle of pleon segment 3 produced and rounded, 2nd joint of peraeopod 



3 not lobed on distal hind corner ... ... ... ... ... ... ... typica 



II. Postero-inferior angle of pleon segment 3 quadrate, 2nd joint of peraeopod 3 lobed on 

 distal hind corner. 



A. Hand of gnathopod 2 in $ with palm shorter than hind margin. 



1. Hand twice as long as broad antarcticus 



2. Hand not twice as long as broad ... ... ... ... ... ... perlatus 



B. Hand of gnathopod 2 in $ with palm longer than hind margin. 



1. Pleon segment 3 dorsally projecting carinata 



2. Pleon segment 3 not projecting. 



a. 2nd joint of peraeopods 4 and 5 oval crenatipalmatus 



b. 2nd joint of peraeopods 4 and 5 distally narrowed porcellanus 



Proboloides typica (Wlkr.) (Fig. 57). 



Walker, 1907, p. 20, pi. vi, fig. 10. 

 Schellenberg, 1926, p. 323, fig. 41. 

 Barnard, 1930, p. 339. 



Occurrence: 1. St. 42. South Georgia. 1 £ 6 mm., 

 2 ?? (1 ovig.) 7-7-5 mm., 7 juv. 3-5- 

 6 mm. 



2. St. 123. South Georgia. 1 $ with 

 embryos 9 mm. 



3. St. 144. South Georgia. 1 ? 7 mm. Fig. 57. Proboloides typica (Wlkr.). 



4. St. 152. South Georgia. 1 $ 7-5 mm. Gnathopod 2 of $. 



5. St. 160. South Georgia. 1 $ 7 mm. 



Remarks. Gnathopod 1, 4th joint apically rounded, with long setae, and a thick 

 brush of fine setules on lower margin, 5th elongate, lower margin with long setae, 6th 

 not quite as long as (dorsal) length of 5th, narrower proximally, szvelling distally to form 

 a transverse palm with rounded angle bearing 3 spines. Gnathopod 2 in S, 2nd and 3rd 

 joints strongly channelled on anterior margins as in antarcticus, 6th longer than broad, 

 palm shorter than hind margin, with a flattish tooth near hinge, and 3-4 crenulations 

 between the shallow median notch and the defining tooth; in ?, 4th joint trapezoidal, 

 lower apex acute, 5th lobed below, with several setae and a dense brush of setules, 6th 

 large, subtriangular, palm subequal to or slightly shorter than hind margin, defined by 

 an acute point within which are 2 stout spines, followed by a series of unequal rounded 

 teeth. 



Peraeopod 3 with 2nd joint not lobed on distal hind corner. 



Postero-inferior angle of pleon segment 3 produced in a rounded lobe. 



These specimens are not exactly like Walker's figures, but the differences in the 

 gnathopods are not so great that they may not be ascribed to growth-changes. 



Distribution. McMurdo Sound, 457 m.; ' Gauss ' winter station, 385 m. 



