82 



DISCOVERY REPORTS 



Ampelisca macrocephala, Lilj. (Fig. 38). 



Walker, 1903, p. 53, pi. ix, figs. 58-61*; 1907, p. 18. 

 Stebbing, 1914, p. 357. 



Occurrence: 1. St. 42. South Georgia. 2 <£<?, 8 ?$ (incl. 4 ovig.) 9-1 1 mm. 



2. St. 123. South Georgia. Many $$, $¥. some ovig. 10-11 mm. 



Description. Body dorsally compressed, but scarcely keeled except slightly on head. 

 Head moderately deep. Corneal lenses 4, upper in the / 

 upper angle of head, lower actually on the lower margin. 

 Postero-inferior angle of pleon segment 3 produced in an 

 acute point , margin above nearly straight ; pleon segment 4 

 with a low triangular ridge dorsally. 



Antenna 1 about half length of antenna 2 in $, two-thirds 

 in <$ . Antenna 2 extending to about 6th peraeon segment ; 

 4th and 5th peduncular joints subequal. 



Mandibular palp with 2nd joint linear, as in the northern 

 macrocephala . 



Peraeopods 1 and 2, dactyls considerably longer than 

 5th and 6th joints together. Peraeopod 5, 2nd joint ex- 

 panded into a nearly evenly rounded lobe, somewhat 

 truncate below, extending to middle of 4th joint, 3rd-6th Fig. 38. Ampelisca macrocephala, 

 joints gradually increasing in length, 6th abruptly Lilj. «. Head. 6. Pleon segments 3 



. . j 1 1 ,, ,.1 and 4. c. Peraeopod z (setae on 2nd 



narrower than cth, narrow ovate, dactyl shorter than 6th. . . "* . ,. r 

 ~ joint omitted). 



Uropod 3 with rami narrow lanceolate. 



Remarks. This form is extraordinarily close to the northern macrocephala , Lilj., and 

 latipes, Steph., but differs in the almost straight hind margin of pleon segment 3 above 

 the produced point, straighter even than in latipes. Gnathopods 1 and 2 are rather 

 stouter than in Sars' figure of macrocephala (pi. Ix, fig. 1), but gnathopod 1 is not as stout 

 as in latipes. Peraeopod 5 is like that of latipes. On the whole this form resembles 

 latipes more than macrocephala. In my opinion this form should be specifically separated 

 from the northern species, as in the case of the two forms of eschrichtii. 



Distribution. McMurdo Sound; Falkland Islands. 



Ampelisca bouvieri, Chevr. 



Chevreux, 1913, p. 96, figs. 7-9. 



Occurrence: 1. St. 27. South Georgia. 1 <$ 19 mm., 1 926 mm. 



2. St. 140. South Georgia. 1 $ 20 mm. 



3. St. 153. South Georgia. 1 9 22 mm. 



Remarks. Chilton (1917, loc. cit., p. 79) in discussing the synonymy of eschrichtii, 

 mentioned that Chevreux in describing his species did not point out the special cha- 

 racters distinguishing it. Chilton without critical discussion places it in the synonymy 

 of eschrichtii. 



