350 TAGE SKOGSBERG 



Philomedes (Ph.) longicornis is mentioned in the same treatise by G. (). Sars as being 

 found, though rarely, both in the mud of the bottom and in the pknkton. 



In 1869 the same author 2)ut forward the notable supposition that Bradycinetus globosus 

 and Philomedes (Ph.) longicornis were females and males of the same species, which he called 

 Ph. globosus. Thus, according to the statement in this work, this species has two kinds of males, 

 Ph. (Ph.) longicornis and the form that is distinguished from the females by a powerful 

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

 short and those with long natatory bristles on the exopodite of the second antenaa. — This 

 author observed the same conditions in a closely-related species, Ph. (Ph.) Lilljehorgi. 



It is certainly true that for a short time Bradycinetus globosus and Philomedes (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 monograph on the s t r a c o d s of the Gulf of Naples G. W. MOLLER, 

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

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

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

 medes kniipfen — Zusammengehorigkeit der Gattungen 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 S gehort; daB 2) die Individuen mit kurzen Schwimmborsten lediglich Jugend- 

 stadien der J oder $ mit langen Schwimmborsten sind. 



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

 aus typischen Bradycinetus die ^ von Philomedes zu ziehen, oder umgekehrt: die o zeigen bis 

 zum Eintritt 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 S bereits die 

 secundaren Geschlechtsmerkmale vor, was Sars in der oben citierten Stelle veranlaBt, von J 

 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 spocinu'ii niii^ht possibly lie a nude, Init did not tiiid tins siiriuisc l)orno out l)y anatoniicai i-xami- 

 iiation. I have since found amongst my preserved specimens many individuals thus filled for swimming and have con- 

 vinced myself that Ihey 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 indiviiluals. I have noticed it also in another species." 

 {I'h. (Ph.) Lilljcborgi) ,,In a few sperimcns" [Hkadv writes: ..In this single example (which though . . . etc.)", an 

 incorrect translation which destroys the wlioh' meaning of Saks's expasltio.i.]" (which though I could not 

 satisfactorily delect the copulative organs. 1 inusl lake for males) llu' lower antennae show another marked peculiarity, 

 the shorter branch being much larger Ihaii ia llir IVmalr, and liaviiig :ni cloiigated nieMibranous terminal joint arnn'il 

 with two sliort si'l.ie. wlliih is rnlirely wanting in llu' Icinales." 



