(m TAOK sKor.sr;Kno 



(with the exception oi one iibnonnal specimen) all specimens at Stage I. were of tlii> elongate 

 type; iit 8tage II. they are never so elongate as at Stage I., although both exhibit a certain 

 amount of individual variation." 



The following information is found in tlie work mentioned: 



Shell: ., Stage I'": The male shell is of about the type reju'oduced by me in Hg. 1 

 above, but not (pute so elongated (length : height = about 1,!> : 1). The female shell is somewhat 

 more elongated than the one given by me in fig. 3 above (, .length may be more than twice the 

 height"). ., Stage 11": The male shell is rather short and high, of about the type reproduced 

 by (t. W. Muller, 1906 a, pi. XVII, fig. 23. Length : height = about 1.7 : 1. The female 

 shell is still higher; length : height = about 1,4 — 1,5 : 1. 



First antenna: ,, Stage I": The e-bristle in the male is furnished with from ten 

 to twelve pairs of spines of the same type and position as has been described by me above. 

 ,, Stage II": This bristle is armed with eight or nine similar piMr^ of spines. 



Second antenna: ,, Stage I": The male endopodite is characterized by clasping 

 organs similar to those reproduced by me above (figs. 7 and 8). The c- and d-bristles (,, basal 

 bristles", according to G. H. FowLEli's terminology) are developed. ,, Stage IT": The clasping 

 organ on the right male endopodite has a marked proximal bend (fig. 209); ,,with no basal 

 bristles". 



,,R o d - s h a p e d org a n: j : ,, Stage I": Of the type reproduced by me above, fig. 4. 

 ,, Stage 11" : ..The general type is that of Stage I, but shorter and pltimper". ?: In both ,, Stage I" 

 and ..Stage II" rather variable; the same tyjjes as U. W. MULLEK observed were fotmd. 



Do ,, Stage I" and ,, Stage 11" really represent two sticceeding stages of one and the same 

 species? I believe that this question must be answered in the negative. The fact which in my 

 opinion forms the strongest argument against this theory of G. H. Fowler's is that in my 

 Antarctic material the oldest larvae were of about the same elongated type as the mature speci- 

 mens. For further information on this point see p. 567 above. 



How are we to look upon ..Stage 11"? As is shown by the quotation given ab(jve the 

 variation in shell-shape was not continuous in the material investigated by U. H. Fow LER ; two 

 centres of variation could be distinguished. This indicates, of course, that the material was 

 not pure from a systematic point of view. It does not seem to me improbable that ,, Stage 11" 

 belongs to a species very closely related to C. rotundata that has already been described by 

 Vt. W. MiiELER, 1906 a; this species is C. nasotuberculata. The reasons for this view are as follows: 

 The shell of C. nasotuherculata has about the same shape as ,, Stage 11"; the length also agrees 

 fairly well; cf. G. H. Fowi.ER, p. 273. The clasping organ of the endopodite on the right second 

 antenna in the mali' is in tliis species of a type closely resembling that which is characteristic 

 f ,, Stage 11"; cf. (i. \\. MiJLLER's fig. 30. jjl. XVIII, 1906a with G. H. Fowler's fig. 209; 

 in both are found what (!. \\. Mt'LLERi describes as: ,,niit auBen wenig abgerundeter rechtwink- 

 li^er Ivke". In addition we nuist note the great resemblance between the rod-shaped organ 

 in |)1. 6, fig. l,s. (J. \\. Miller, 1894 and G. H. Fowler's fig. 208. This figure in G. W. Mt'LLER 

 is reproducetl from a specimen of the same short type of shell and with a similarly shaped clasping 

 organ on the male right second antenna as in ,, Stage 11". In the work just mentionetl it was 



< I 



