Cypridina 



Monopia 



studies on riiniine Ostracotls 193 



This sub-family consequently comprises at the present moment in my opinion five natural 

 recent genera altogether, one of them consisting of two and another of five sub-genera. 

 Genus Crossophorus 

 „ Codonocera 

 ,, Gigantocypris- 



Sub-genus Doloria 

 „ Vargtda 



„ Macrocypridina 



„ Cypridina 



„ Siphonostra 



,. Monopia 



Cypridinode.ft. 



Is it possible to establish the mutual relationships of these units? Are there anv The mutual relmion- 

 forms within this sub-family that can be indicated as being more primitive than the others? ■'''''■' "■^ '''^ ""'''■ 



On account of the great uncertainty and incompleteness that, as I have pointed out Difficulties. 

 above, distinguishes a great many of the descriptions of the forms belonging to this sub-family, 

 it may perhaps seem too early to attack these difficult problems already. The result is destined 

 a priori to be both meagre and uncertain. In spite of this I shall make an attempt in this 

 direction on account of the importance of the enquiries. 



To obtain an answer to these questions I have undertaken as detailed a comparison 

 between these groups as is possible with the incomplete diagnoses at my disposal. In doing 

 this as great a number of characters as possible have been taken into consideration. If 

 I were to put forward here all the results arrived at during this work it would be a very 

 comprehensive statement. It may, however, not be convenient to do so on account of the 

 great incompleteness and uncertainty of the greater part of the diagnoses in question. Only 

 the main results of this investigation will be given below. 



Besides the incompleteness and uncertainty of the majority of the diagnoses of genera 

 and species previously given, the difficulty in deciding the classificatory value of the different 

 characters is an obstacle in determining the phylogenetic position of the various units. The 

 qiiestion continually arises : is the resemblance the result of common inheritance or of convergence? 

 According to what I myself have observed, convergence appears to be by no means 

 rare within this sub-family. In any case it is quite certain that it occurs, rather good evidence 

 of it being found, as for instance in the furca. 



The furca seems originally within this group to have been characterized by the fact 

 that its claws were well defined from the lamellae and decreased uniformly in length the more 

 proximally on the lamellae they were fixed. The fact that this furcal type prevails in all the 

 families belonging to the sub-ordo Cypridiniformes supports this assumption. Within the 

 sub-famil)'- Cypridininae we find a furca of this type .in apparently all species of Gigantocypris, 

 Codonocera, Doloria, Macrocypridina, Monopia and Cypridinodes. \\'ithin the sub-genera 

 Cypridina (sensu meo), Vargida and Siphonostra we find, however, other furcal types as well. 

 In the first of these three sub-genera the following furcal types may be distinguished: 



/ooloE. hidr.iB. Uppsala. Suppi.-Bd. I. 2.> 



