studies on iiiariiie Oslratods 507 



I have decided, though only after much hesitation, to follow the example of this writer 

 (1906 a) in identifying J. D. Dana's two species Halocypris bremrostris and H. inflata, first mth 

 each other, and secondly with the form described above. This writer does not give any argu- 

 ments in favour of this procedure of his, and yet it seems to need to be particularly well supported 

 by reasons; it is certain, however, that he does not base these identifications on a re-examination 

 of J. D. Dana's original material. — J. D. Dana's descriptions and figures of the forms in question 

 are unfortunately too incomplete and uncertain to permit of a quite certain identification of 

 the species. The only thing there really is for one's guidance is the shape of the shells; the limbs 

 are too incompletely discussed in the original descriptions of these forms and are too uniform 

 in this genus to be used as material for proof in this question. With regard to the shape of the 

 shells there is, however, a by no means complete agreement between the figures given by 

 J. D. Dana and those given by me above (or with those worked out by G. W. MUller, 1906 a); 

 on the contrary, apart from the figures of the shells as seen from below, there are not inconsid- 

 erable differences to be observed. The greatest resemblance is to be found between J. D. Daxa's 

 figure of the shell of H. brevirostris as seen from the side (1852, pi. XCI, fig. 9 b) and the figure 

 given by me above of the small male from Station 116 of the Swedish Antarctic 

 Expedition. The resemblance between these figures is, as a matter of fact, so great that 

 it forms a very strong argument in favour of identity. There is less resemblance between J. D. 

 Dana's profile figure of H. inflata (1852, pi. XCI, fig. 8 b) and the specimens investigated by me. 

 This figure resembles most closely — by its great height — the type of shell in the females 

 investigated by me. It is possible that J. D. Dana's species H. brevirostris corresponds to tlie 

 male and H. inflata to the female of the forms re-described by me above. This assumption is 

 supported by the length of the shells as well as their shape; J. D. Dana gives a length of 

 1,6 mm. (one sixteenth of an inch) for H. brevirostris and 1,7 mm. (one fifteenth of an inch) 

 for H. inflata. It is impossible, however, to be quite certain in this matter before the specimens 

 investigated by J. D. Dana have been re-examined. 



On the other hand I was unable to accept G. W. MClleh's choice of the name for this form 

 (H. inflata). In J. D. Dana's main work, 1852, H. inflata is certainly placed before H. brevirostris, 

 but in , .Conspectus Crustaceoru m", 1849, the preliminary treatise of this work, 

 H. brevirostris is, on the contrary, placed before H. inflata. According to Art. 26 c of the inter- 

 national rules for nomenclature* H. brevirostris should thus be used as the name of this species. 



There are no figui-esof H. brevirostris, 3. hvnmcii, 1860; the statement: „the anterior notch is 

 single in one valve and double in the other" is, however, a strong argunicnt in favour of the identi- 

 fication made above. It is fairly certain that the same author's species H. Toynbeeana is identical with 

 the male of the species dealt with me above; the agreement in the shape of the shell is striking. 



C. Glaus, in his little essay on „Die Gattungen imd Arteu der Halocypriden**, 1874 a. 

 describes (p. 177) a new species of this genus, H. concha. (This is described in more detail in 



• Zoolog. Anzeigor, Bil. XXVIII, p. 5"y. 

 •• C. Claus writes as follows in this work, p. 178, wilh regard to the two forms of J. D. Ijana's just mentioned: 

 ,,Hierher gehoren audi Dana's //. inflata iind brci-iroslris. die jedoeh als Arlen nieht j.w Irennen siiid iind anssihiieUlich 

 nacli VVeibrhen besc-Jirieljeii warden". Claus was rons«iuently tin- first to identify these two forms with each other. 

 In later works of C. Glaus's these species are not menlioned. 



