W. M. TATTERSALL. 



JVIr. Hodgson (1902) described two species as new, Euphausia glacialis and E. australis, 

 collected by the ' Southern ( 'ross ' South Polar Expedition. Both species arc 

 synonymous with E. xuperbti, Dana, so that previous to 1903 only four Antarctic, 

 species of Schizopoda were known, viz., Eucopia aust rails, Dana, Euphausia superba, 

 1 )ann, Thysanoessa macrura, G. 0. Sars, and Pseudomma x/trxi, Will.-Suhm. 



Of the recent expeditions to the South Pole, which number seven, the results of 

 the Schizopoda of the French Antarctic Expedition have been published in full, and of 

 the ' Valdivia ' Expedition in part only. M. Coutiere (1906) notes from the French 

 Antarctic collections, Enphaasia superba, Dana, E. similis, G. 0. Sars, Thysanoessa 

 macrura, G. 0. Sars, and Antarctomysis maxima (Hansen, MS.), a species also recorded 

 in the preliminary note on the present collection. 



Preliminary descriptions have been published of two Antarctic Mysidse collected 

 by the. ' Valdivia ' (Illig, 190G), Dactylerythrops arcuala and Echinomysis chum. The 

 first of these is synonymous with a species Dactylamblyops hodr/soni, described below. 



This completes the bibliography as regards purely Antarctic Schizopoda, though a 

 number of sub-Antarctic species are known. 



Ten of the thirteen species collected by the ' Discovery ' were taken in Antarctic 

 waters, and when, as we have seen above, the total previously recorded species number 

 seven, it will be recognised that the present collection has added considerably to our 

 knowledge of South Polar species of this group. 



The most abundant species in the collection is a small Euphausia, E. crystal- 

 lorophias, H. and T., which evidently has its head-quarters under the ice, since all the 

 specimens were collected from ice-holes at Winter Quarters, and none were met with in 

 the open sea. On the other hand, the dominant species of the collections from open 

 Antarctic waters are Eupliauxia xuperba, Dana, and Thysanoessa macrura, G. 0. Sars. 



The abundant material of the first-named species has afforded opportunity for 

 some observations on the sexual characters and life history of the species, with the' 

 result that four other species, hitherto regarded as distinct from E. superba, must now 

 be allocated to its synonymy, having been founded either on characters which are 

 sexual and not specific," or else from immature specimens. 



The scarcity of fully grown males of E. superba seems worthy of note. This fact 

 seems to be established by the results of the various collections of which we' have 

 knowledge, since, so far as I am aware, the only one recorded is Sars' ' Challenger ' 

 specimen. M. Coutiere (1906), it is true, notes that male specimens were more 

 numerous than females in the collection he examined, but it is equally clear that none 

 were fully grown, since the largest measured only 45 mm., and was in the stage pre- 

 vious to the last moult into completely grown specimens. There are no fully-grown 

 males in the ' Discovery ' collections, but to judge from the development of the copulatory 

 apparatus on the first pleopods, many of them must be sexually mature at any rate. 



Thysanoessa macrura, G. 0. Sars, too, seems never to have been previously met 

 with in full-grown condition, and but very few of the ' Discovery ' specimens can be 



