'M^(^ TACK sKonsni^no 



Philoitit'dt's ( Ph.) longicornis is niciititnicd in tin- smiiic trr.itisc Iiy (!. O. (^\i;s as Ix'iiin; 

 fiHiiul. tli(>uj:li rarely. l)()tl> in th<' mud nf thr liollmii aii<l in the |ilaiikt(in. 



In IStil) tlu< saino autlmr put lorwaiil llu' uolabK- su|j|)i)situ)u lliat Jiritdi/ciiit/us (jUibitsiis 

 and PliilometU's (Ph.) longicornis wero iVmalos and males of the same species, which he calh'd 

 /'//. glolxKiu.'i. Tims, according to the stateiiiful in this \v(iil<. tiiis species has two kinds of males. 

 Ph. (Ph.) longicornis and the form that is distinguished lium the iVmah-s by a powerful 

 development of the endopodite of the second antenna, and two kinds ol females, those with 

 short and those with long natatorv bristles on the exopodite of the second antenna. — This 

 autlior observed the same conditions in a closely-related species. Ph. (Ph.) Lil/jchon/i. 



It is certainly true that for a short time Bnulycineius globosus and Philomcdcs (Ph.) 

 longicornis were still looked upon as belonging to two separate genera, as, for instance, in 

 G. S. Brady's work of 1871, which is exceptionally inconsistent in dealing with this problem; 

 the reasons in support of G. 0. Sars's supposition were, however, so strong that this author's 

 view that we are concerned with males and females of the same genus and even of the same 

 species was very soon completely accepted. 



In his large monograjjli on the Ostracods of the Gulf of Naples G. W. MtlLLER, 

 at the same time as be affirms the union of the genera Bradycinetus and Philomedes, puts forward 

 a new view with regard to the dimorphism that G. 0. Sars had pointed out among males and 

 females. On this ML'LLER writes, p. 187 : „Die Fragen, die sich nach dem Gesagten an Philo- 

 medes kniipfen — Zusammengehorigkeit der Gattiingen Bradycinetus und Philomedes, Existenz 

 von zweierlei $ bei B. — beantworten sich an der Hand der Entwicklungsgeschichte, resp. mit 

 Hiilfe von Zuchtversuchen sehr einfach dahin, daB 1) Bradycinetus als ? oder als Jugendform 

 zu Philomedes als cj gehort; daB 2) die Individuen mit kurzen Schwimmborsten lediglich Jugend- 

 stadien der ^ oder $ mit langen Schwimmborsten sind. 



Die Beobachtimgen, auf welche ich diese Satze griinde, sind kurz folgende. Es gelingt. 

 aus typischen Bradycinetus die (J von Philomedes zu ziehen, oder umgekehrt: die c? zeigcn bis 

 zum ELntritt der Geschlechtsreife in der Schale, sowie im Bau der 1. Antenne und der FreBwerk- 

 zeuge durchaus den Charakter der geschlechtsreifen ?. (In der Gestalt des Nebenastes der 

 2. Antenne und in der Pigmentierung des Auges bereiten die letzten Stadien des c? bereits die 

 secimdaren Geschlechtsmerkmale vor, was Sars in der oben citierten Stelle veranlaBt, von (S 

 von Bradycinetus zu sprechen.) 



Fur den zweiten Satz vom sogenannten Dimorphismus der $ will ich folgende Beobach- 

 tungen geltend machen. Nie ist es mir gelungen, bei einem Weibchen mit kurzen Schwimmborsten 



I thought that the specimen mif,'ht possiljly he a male, hut diJ not fiiiil this surmise borne out l)y anatomiial exami- 

 nation. 1 have since found amongst my jireserved specimens many individuals llius fitted for swimming and have con- 

 vinced myself that they like those with the short setae are females." (Brady's translation is not quite correct here. 

 He writes: ,,.... and have convinced myself that those with the short setae are females"). „The peculiarity is not 

 one of age merely, for I have found it in both young and old individuals. I have noticed it also in another species." 

 [Ph. (Ph.) Lilljeborgi) ,,In a few' specimens" [Bkadv writes: ,,In this single example (which though . . . etc.)", an 

 incorrect translation which destroys the whole meaning of Sars's expDsitio i.]' (which though I could not 

 satisfactorily detect the copulative organs, I must take for males) the lower antennae show another marked jjcculiarity, 

 the shorter branch being much larger than in the female, and having an elongated membranous tiMiiiinal joint armed 

 with two short setae, which is entirely wanting in the females." 



