288 DISCOVERY REPORTS 



Amallocystis fagei Boschma 



Staphylocystis racemosus Macdonald, 1927, p. 780. 

 Amallocystis sp. Einarsson, 1945, p. 158. 

 Amallocystis fagei Boschma, 1948, p. 448. 



Material : 



St. 665 (51° 41' 30" S, 29^ 58' 45" W), 17. iv. 1931, net TYFB, depth of net 250-0 ni., i ex. on Euphaiisia frigida 

 H. J. Hansen. Transverse sections of host, Delafield's haematoxylin (Fig. 3^). 



St. WS 770 (46° 03' S, 66° 34' W), 21. X. 1931, net NiooB, depth of net 57-0 m., 6 ex. on Euphausia vallentini 

 Stebbing. Three specimens figured in Pi. XXXVIII, figs. 1-5, 10; one specimen transverse sections of host, 

 Ehrlich's haematoxylin (PI. XXXIX); one specimen longitudinal sections of host, Delafield's haematoxylin (PI. XL). 



St. 712 (28° 02' 06" S, 43° 09' 30" W), 28. X. 1931, net TYFB, depth of net 224-0 m., i ex. on Euphausia recurva 

 H. J. Hansen (PI. XXXVIII, fig. 6). 



St. 733 (62" 56' 42" S, 75"o2' W), 21. xi. 1931, net NiooB, depth of net 84-0 m., i ex. on Euphausia frigida 

 H. J. Hansen. 



St. 748 (55° 29' 24" S, 54" 13' 48" W), 29. xi. 1931, net N looB, depth of net 180-0 m., i ex. on Euphausia frigida 

 H. J. Hansen. 



St. 751 (51° 28' 42" S, 49° 17' 42" W), I. xii. 1931, net NiooB, depth of net 104-0 m., 2 ex. on Euphausia frigida 

 H. J. Hansen. One specimen figured in PI. XXXVIII, figs. 8 and 11; one specimen longitudinal sections of host, 

 Ehrlich's haematoxylin (Fig. 4). 



St. 766 (58° 51' S, 36° 54' W), 10. xii. 1931, net NiooB, depth of net 102-0 m., i ex. on Euphausia frigida H. J. 

 Hansen. Transverse sections of host, Delafield's haematoxylin (Fig. 30). 



St. 869 (43° 56' 30" S, 103° 24' 18" E), 5. V. 1932, net N looB, depth of net 68-0 m., i ex. on Euphausia lucens 

 H. J. Hansen. 



St. 871 (39° 32' 06" S, 107° 06' 24" E), 7. V. 1932, net NiooB, depth of net 240-100 m., i ex. on Tliysanoessa 

 gregaria G. O. Sars. Transverse sections of host, Ehrlich's haematoxylin (Fig. 5). 



St. 872 (37° 09' 06" S, 108' 47' 12" E), 7. V. 1932, net N looB, depth of net 128-0 m., i ex. on Euphausia hemigibba 

 H. J. Hansen (PI. XXXVIII, fig. 9). 



St. 892 (52° 48' 30" S, 137° 00' 24" E), 31. V. 1932, net N looB, depth of net 93-0 m., i ex. on Euphausia vallentini 

 Stebbing. Transverse sections of host, borax carmine (Fig. 2). 



St. 963 (52° 01' S, 139° 13' 12" W), 14. ix. 1932, net N lOoB, depth of net 320-128 m., i ex. on Euphausia vallentini 

 Stebbing. Type specimen, transverse sections of host, Delafield's haematoxylin (Figs, i, 96). 



St. 965 (47° 16' 54" S, 132" 25' 06" W), 16. ix. 1932, net NiooB, depth of net 310-132 m., i ex. on Thvsanoessa 

 gregaria G. O. Sars (PI. XXXVIII, fig. 7). 



St. 1056 (50° 18' S, 37° 04' 30" W), 4. xii. 1932, net N 100 B, depth of net loo-o m., i ex. on Euphausia vallentini 

 Stebbing. 



The first record of this parasite undoubtedly is the specimen on Meganyctiphanes norvegica (M. Sars) 

 identified by Macdonald (1927) as Staphylocystis racemosus (Coutiere). As the author states that the 

 parasite occurred on the carapace of this host, and as the host belongs to the Euphausiacea, it cannot 

 have been the species of Coutiere which lives on the underside of the abdomen of a host belonging to 

 the Caridea. 



More particulars on the parasite of the Euphausiids are given by Einarsson (1945). This author 

 states that the parasite is closely allied to Amallocystis racemosus (Coutiere), A. fasciatus Page and 

 A. capillosus Page, and remarks that most probably it is a species new to science, which he provisionally 

 indicates as Amallocystis sp. Einarsson states that this parasite, which he found on Thysanoessa inermis 

 and Th. raschii, is always attached to the dorsal side of the carapace, usually in the middle or behind 

 the middle, but in rare cases in the region of the stomach. Interesting is the following remark (Einarsson, 

 1945, p. 158): 'Usually there are more than one bundle of trophomeres and gonomeres present, most 

 often three or more, which seem to have no connection with each other.' This points to the fact that 

 in the North Atlantic, specimens of Thysanoessa may be infested by a number of separate individuals 

 of the parasite. 



Einarsson 's fig. 81 distinctly shows that his parasite corresponds with those dealt with in the present 

 paper. His figures of transverse sections of a specimen of Thysa?ioessa with Amallocystis sp. (loc. cit., 

 fig- 83 b, c) show the organ of fixation in its most strongly developed region, and the ramifications of the 



