9 o 



B. II, G. b., p. 13, Taf. VII, Fig. 8) can not be an adult or subadult form but must be a 

 large larva ; according to Ortmann's description and figures the shape of the antennulae with 

 their extremely short flagellum and the very long spine from the outer angle of their basal 

 joint is purely larval, and the same is certainly the case with the long dorsal spine from the 

 hind margin of the carapace ; the fifth pair of thoracic legs are short and the telson is some- 

 what longer than the uropods, but both these features are found in advanced larvse or very 

 young specimens. Judging from the shape of the frontal plate and rostrum I suppose that the 

 animal may be the larva of a species of TJiysanopoda. 



According' to my examination in the British Museum of the type of Eupliausia lanei 

 Holt & Tatt. it is a less than half-grown specimen of MeganyctipJianes norvegica M. Sars; the 

 lobe or leaflet on the first antennular joint had been broken off which made the very small 

 specimen somewhat difficult to recognize. The name E. lanei is therefore to be cancelled. 



TJiysanopoda Krohnii Brandt, 1851 (Krebse, in Middendorff's Sibirische Reise, Bd II, 

 I, p. 127) from the Mediterranean is quite insufficiently described and has been overlooked by 

 all authors. Guessing that it might be identical with EupJiausia Mülleri Claus I asked Prof. 

 A. Birula to give me a description with figure of the lobe from first antennular joint, and he 

 most kindly sent both, which proved beyond doubt that my supposition was correct, as the 

 lobe mentioned is extremely characteristic and quite different from those met with in any other 

 species of EupJiausia known from the Mediterranean or the Atlantic ; consequently this most 

 common European species is to be named E. Krohnii Brandt. 



In Buil. Mus. Océan. Monaco, N n 42 (1905) I proved that among the four species of 

 Euphausia established by Dana only E. supcrba is recognisable and valid, while the others, 

 E. pellucida, E. splendcns and E. gracilis, are to be cancelled, as the types are lost and the 

 descriptions and figures quite insufficiënt for recognition of the forms. Furthermore I showed 

 that E. pcllucida Dana sens. Sars is collective ; I described four species with two pairs of lateral 

 denticles on the carapace, viz. E. Mülleri Claus, E. recurva H. J. H., E. mutica H. J. H., and 

 E. brevis H. J. H., while a fifth species, E. diomcdea? Ortm., was mentioned with some doubt, 

 as I had no specimen agreeing with his figure. The study of a vast material from the Pacific 

 and the "Siboga" expedition showed, that E. mutica as established by me in 1905 still comprises 

 two allied but well separated species, one of which can keep the name E. mutica, while the 

 other is E. diomcdecr Ortm., as the structure of the antennulae and the male copulatory organs 

 is quite similar in specimens possessing the character, viz. a highly expanded frontal plate, on 

 which Ortmann established his species, and in specimens with that feature not developed, and 

 as specimens from the Pacific vary much in the size of the frontal plate and rostrum. 



In 1894 Ortmann founded a species, Eup/iausia pseudogibba, as different from E. gibba 

 G. O. Sars established on specimens from the Pacific. In the Monacoq^aper mentioned I cancelled 

 Ortmann's species, as the characters pointed out by him seemed to me to be invalid. But the 

 study of the copulatory organs of the specimens similar to E. gibba captured by the "Siboga" 

 together with selected specimens from the Atlantic and the Pacific gave the result, that now 

 I know four species, the females of which are so closely allied that frequently they are difficult 

 to separate with absolute certainty, while the copulatory organs of the males show extremely 



