4 COPEPODA 



relating to depth, salinity and temperature, and that they have missed the opportunity of giving a new 

 description of several species, imperfectly known. In the following I have tried to collect the 

 facts, found under each Station in their paper, under each species, and it will be evident that I sometimes 

 differ from the two authors in their conclusions from these very facts. It seems to me, that these 

 small defects, give prominence to the surprising amount of useful information, which makes this 

 expedition one that may in several ways be regarded as an example. 



With the useful papers of Damas, Paulsen, Esterly, Kraeeft and Oberg I am going to 

 deal later on. 



On systematic Characters. 



In addition to the systematic characters, used by most authors, I think that good characters 

 may be found in several organs, the importance of which has been overlooked or underestimated: 

 viz., the rudimentary appendages of the male, the structure of the genital apparatus in the female, the 

 system of glands in the natatory legs and the more detailed structure of the labrum and labium. 



In addition to the good characters, which are generally found in the fifth pair of legs in the 

 males, good characters are f. inst in species of Euchirella found in the rudimentary mouth appendages 

 as well as in the first pair of legs, which differs distinctly from that of the female. 



It is generally recognised, that the structure of the vulva is most important from a systematic 

 point of view, but as it is often rather complicated, the figures of it are often rather imperfect. In 

 the description of the nearly related species of Euchatc I have given a somewhat more detailed 

 description, well aware, that a complete dissection is quite necessary for understanding the morpholo- 

 gical as well as the systematic importance of all these lists and bars; a study of this nature would 

 certainly have enhanced the value of this paper but would have delayed its publication too much. 



Cutaneous glands and pores, through which their contents are discharged, have been described 

 and mentioned by different authors, who, however, like Giesbrecht took most interest in these 

 organs in species in which they were probably luminous. 



The glands which are found in the natatory legs do not seem to have interested the authors 

 very much; Giesbrecht has in his great paper figured glands, filled with globules of oil (?), in 

 the legs of Etichirella rostrata (pi. 15 fig. 27) but as far as I know or remember, they have not 

 been mentioned by others. As these glands are often very prominent organs and generally are connected 

 with the ducts, which are often filled with drops of oil, I think they are of great importance for the animals; 

 they are generally not unicellular as several elongated nuclei are often seen at the base of an elon- 

 gated sac; a study of the anatomy and histology of these glands should be very interesting 011 fresh 

 material, but did not fall within the scope of this paper. As the glandular ducts open in a rather 

 uniform way in the natatory legs, and as the exact number and position of these glandular pores 

 which are alway placed on the anterior surface sometimes have a systematic importance of no small value, 

 I have carefully examined them in the different species, to the description of which I refer for details. 

 The original number of pores seems to be the following: one near the base of the external spine 

 (Se) of the third basipodite, one corresponding to the Se of the two first outer segments and three, 

 corresponding to the 3 Se of the third outer segment (cf. pi. I fig. 3e); this number is reduced in 



