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(with the exception of one abnormal specimen) all spécimens at »Stage 1. were of the elongate
type; at Stage II. they are never so elongate as at Stage L, although both exhibit a certain
amount of individual variation.“
The folio wing information is found in the work mentioned:
Shell: „Stage I“: The male shell is of about the type reproduced by me in lig. 1
above, but not quite so elongated (length : height = about 1,9 : 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 II“: The male shell is rather short and high, of about the type reproduced
by G. W. MÜLLER, 1906 a, pl. XVII, fig. 23. Length : height = about 1,7 : 1. The female
shell is still higher; length : height = about 1,4—1,5 : 1.
First an tenn a: „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 pairs 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. Fowler’s terminology) are developed. „Stage II“: 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 o r g a n: <$: „Stagel“: Of the type reproduced by me above, fig. 4.
„Stage II“ : „The general type is that of Stage I, but shorter and plumper“. Ç: In both „Stage I“
and „Stage II“ rather variable; the same types as G. W. MÜLLER observer! were found.
Do „Stage I“ and „Stage II“ really represent two succeeding stages of one and the same
species? I believe that this question must be answered in the negative. The faet 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 II“? As is shown by the quotation given above the
variation in shell-shape was not continuons in the material investigated by G. H. FOWLER; 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 II“
belongs to a species very closely related to C. rotundata that has already been described by
G. \V. MÜLLER, 1906 a; this species is C. nasotuberculata. The reasons for this view are as follows:
The shell of C. nasotuberculata has about the same shape as „Stage II“; the length also agrees
fairly well; cf. G. H. FOWLER, p. 273. The clasping organ of the endopodite on the right second
antenna in the male is in this species of a type closely resembling that which is characteristic
of „Stage II“; cf. G. W. Müller’s fig. 30, pl. XVIII, 1906 a with G. H. Fowler’s fig. 209;
in both are found what G. W. MÜLLER describes as: „mit außen wenig abgerundeter
rechtwinkliger Ecke“, ln addition we must note the great resemblance between the rod-shaped organ
in pl. 6. fig. 18, G. \V. Müller. 1894 and G. H. Fowler’s fig. 208. This figure in G. \V. Müller
is reproduced 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 mentioned it was
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