M 



I \(il-; SKOCSHKI! 



Miillfr's opi- 

 "/ Ihe l'r»i- 



Lifr. 

 Shell. 



iffnirnlalion nf ihr 

 hody. 



Ilfarl. Alinienlari/ 

 <)r««?ii.«. Eyes. 



.\iitiihfr of liml).--. 



FimI ant f nun. 



Sernnd nnlrnim 



tlu'.sf. C. I'l.M s ami ii. Aim. 1'"i>i iIu> iimsdh it sfnucd td me llml tlic iiid.st (il)\i(His coiirsf in 

 (lisoussinji this pr()l>loin was to luit in\ answer into tlic Jonn o 1' a criticism of G. W. MClleh's 

 exposition of tlu' results gainod l>y him. 



(.'. \\ . MilLLKR depicts thr litV. organization and development of the Protostra cods 

 on tlu» whole as follows: 



The P r o t o s t r a o d s were freely swimming organisms, hut did not travel far 

 from the hottoni. often attaching themselves to hydrophytes ,,ohiie indessen umherzukriechen"*. 



Thev already had a calcified shell which enclosed the whole body and which was shut 

 bv a closing muscle which went through the body. The shell was ,,vermuthlich" characterized 

 hv a rostral incisiir ..fiir den .Vustritt des AuBenastes der 2. Antenne" and by an arched ventral 

 margin. 



The body was segmented externally; there were at least eleven segments 

 behind the head, of which only some had limbs. 



A heart was developed. The alimentary o r g a n s were of the same simple 

 t\'pe as in the recent C v ]) r i d i n i d s. There were well-developed c o m p o ti n d lateral 

 e y e s and an u n p a i r e d m e fl i a ii eye divided into three parts. 



There were eight pairs of limbs, and a ninth had perhaps already become employed as 

 a copulatorv organ. Only four of the limbs belonged to the head; the appendage corresponding 

 to the second maxilla of other Crustacea was absent. 



The first antenna had eight joints. It was probably most similar to that of the recent 

 C V p r i il i n i d s, which is a sensory and a locomotory organ at the same time. „Von einer 

 solchen Form konnte sich ebensowohl die vorwiegend der Bewegung dienende Form der Podo- 

 copa, wie die ausschlieBlich oder fast ausschlieBlich als Sinnesorgan fungirende mancher Myodo- 

 copa entwickeln. Unzweifelhaft hat ein Wechsel, der zum Ueberwiegen der einen oder anderen 

 Function gefiihrt hat, wiederholt stattgefunden." 



Second antenna: — This had a two-jointed protopodite and a well-deve- 

 loped endo- and exopodite. The endopodite was four-jointed, the exopodite composed of a 

 rather large number of joints. Of the recent Ostracods the Polycopids woidd 

 have the most primitive second antenna; these forms would differ from the original type chiefly 

 in the structure of the protopodite. The protopodite of this limb would have had a very different 

 fate in the Cypridinids, Halocyprids and Polycopids on the one hand 

 and in the other Ostracods on the other. In the former groups the two protopodite joints 

 have pointed in the same direction and then gradually have been quite united to each other. 

 In the latter the protopodite was distinguished by the fact that the two joints together formed 

 an upward pointing knee; in most of them it became single-jointed afterwards by the total 

 disappearance of the distal joint; this joint is still found only in the genus Cytherella. In the 

 Cypridinids and the Halocyprids the endopodite is more or less completely 

 reduced. ,,DaB bei einer fast aiisschlieBlichen Verwerthung der 2. .\ntenne als SchwimmfuB 



• G. W. MiJLLER writes, p. 198, that thi'V were ,,in der Lebensweise den Halo (; y p r i d e ii am luichsleir'. 

 When he wrote this, he was of the opinion that the Halocyprids live chiefly at the holtoni and ..niii' 

 zeitweilig schwimmend aufsteigen". 1894. p. 1.1: of course he gave ii]i tliis opinion later on. 



