296 



TAGE SKOGSBERG 



Supposed 



relationship 



to Philomedes. 



Synonymy. 



The 1st antennae 



organs for taking 



up food? 



Proportion lietween 

 males and females. 



Periodicity of 

 reproditrtion. 



Colour of the 

 larfae. 



Shell of the lo.rvae. 



explained as being due partly to obvious inaccuracies on the part of G. S. BRADY and partly 

 to the superficiality of the description. With regard to the shell this author writes as follows: 

 ,,the convexity of the sub-rostral cleft has a fringe of numerous slender spines, which are long 

 in the middle of the series and gradually smaller towards the ends." This series of spines 

 corresponds to the selvage. Further, if we are to judge from fig. 1, pi. X^"I, the shell is 

 characterized by a long row of short medial bristles along the anterior side of the rostrum in 

 front of the row of bristles that is mentioned in the description I have given above and a shorter 

 row of similar bristles within the two bristles close to the inner edge of the incisur. In both 

 these cases it is clear that there has been confusion between bristles and pores on the margin 

 of the shell. According to Brady's figures there appear to be other divergencies in the pro- 

 portion between the bristles on the end joint of the mandible and in the fact that the end joint 

 of the maxilla has only two c- and two d-bristles. 



It may be pointed out as a curious fact that G. S. Brady thought that he could observe 

 a certain agreement with regard to certain characters between this species and — the genus 

 Philomedes. ,, Provisionally, however, it maybe referred to the genus (7(/pn(lwa, though some of the 

 characters show an approach to Philomedes.'' Such a statement cannot of course be explained 

 unless we assume that this author did not have any detailed knowledge of the genus Philomedes. 



There are many reasons in favour of G. W. MCller's assumption that Cypridina obesa 

 Vavra is a larva of the species dealt with above. In investigating a larva of the latter species 

 with a shell of about the same length as that given for C. obesa, I found, however, that if this 

 identification is correct, Vavra must have committed not insignificant mistakes with regard to 

 almost all the organs in his description and reproductions. When, however, one takes into 

 consideration the superficial method that evidently has been employed by this author in working 

 out the rest of the Ostracod material brought home by the ,,P 1 a n k t o n - E x p e d i t i o n", 

 such mistakes do not seem at all unlikely to have occurred. 



The majority of the specimens of this species investigated by me, both males and females, 

 had the long end-bristles of the first antenna stuck in the pharynx. When some of these 

 specimens were dissected, it was observed that the ends of these bristles were rolled up in 

 the stomach. This observation strongly supports the idea that these limbs are used to help 

 in taking up food, a fact that has not been previously known. It is to be noted, however, that 

 among all the very numerous specimens of other species belonging to this famil}' I have never 

 observed this phenomenon. Does this support the idea that it is only in the species treated 

 above that this method of taking in food occurs? 



In the material of this species investigated by me the males were somewhat fewer than 

 the females but only very slightly so. 



Among the mature females there were some with and some witliout eggs or embryos 

 ill the brood chamber in the samples from May as well as in those from July. 



All the larvae, even those in the last larval stage, had no pigment, except on the stomach 

 (cf. G. W. MfJLLER, 1906a, p. -ISO). Some mature females were considerably lighter in colour 

 than tlie others; these had probably just undergone the last larval moult. 



The larvae in the last larval stages have a shell of about the same shape as the mature males. 



