80 RECORD OF CURRENT RESEARCHES RELATING TO 



seems to shod on the pliylogeny of some of the Crustacea. Among 

 the Branchiopoda, which may be regarded as the stem-form of the 

 Cladocera, it is greatly developed not only in the larval stage, but 

 throughout life (Apus, Branchipus, Claus) ; in Artemia it disappears 

 in the adult form (Leydig), In the Estherida it has as yet been only 

 observed in Limnadia, but it is also to be found in Estheria and 

 Limnetis ; in a species of the former it was observed to form a large 

 shield, distinctly marked off, and consisting of nucleated cells with 

 coarsely granular contents ; this was the arrangement in the larva, 

 but in adult specimens of other species of the same genus it was 

 found to be proportionately small ; Limnetis has an oval cervical 

 shield. In the Cladocera this organ is likewise to be observed ; the 

 larval Moina rectirostris has one, but it is lost in the adult ; in 

 M. paradoxa it is retained throughout life. The organ has also been 

 found in the embryo of Gammarus, though it is as yet unknown 

 among the Copepoda or Thoracostraca, save for certain indications 

 presented by the larva of Cyclops serrulatus and Ergasilus Sieboldi. 

 This important paper is illustrated by 76 figures. 



New or rare Crustacea from the Coasts of France.* — In this 

 (twenty -ninth) communication M. Hesse describes ten new Crustacea, 

 seven of which belong to the genus Cycnus Kroyer, and the remaining 

 three to Kroyeria Van Beneden. Belonging to the sij)honostomatous 

 division of the Copepoda, they attach themselves to the branchiae of 

 various fishes ; small in size and really transparent they get a reddish 

 colour from the blood they suck, and they would be with difiiculty 

 distinguished from the branchife, were it not that their dark-coloured 

 ovigerous tubes are so long as to project from the rest of the body. 

 As to Kroyeria, M. Hesse states his belief that they would be better 

 placed with the Pachycephalida than with the Peltocephalida, but he 

 does not consider that he is entitled to sj)eak at all dogmatically on 

 the subject. 



Dealing with their "biologie," the author says that the sudden 

 change of condition to which the species in question were subjected 

 makes it impossible for him to say very much on the subject. They 

 are with difficulty separated from the branchife, and the attempt to 

 remove them is often accompanied by mutilation of the specimens ; 

 it is, however, necessary to do so, for the mucus in which they are 

 encased putrefies rapidly. The species of Kroyeria exhibited the 

 greater amount of activity, and when we compare ti e structure of 

 their appendages with those of Cycnus we find greater d 'fferences than 

 would be expected in forms living under very much tl e same condi- 

 tions. The mouth is not only similar in function but in structure ; 

 though the form of the cephalic region differs considerably ; in Cycnus 

 it is widest diagonally, and in Kroyeria longest vertically ; in the 

 former there are two and in the latter three " rings attached to the 

 head." The females differ not only in having in the one case broad 

 and short ovigerous tubes containing a few large ova, and in the other 

 long narrow tubes with closely packed eggs, but in the former (Cycnus) 



* 'Ann. Sci. Nat.,' viii. (1879) art. No. 11. 



