Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 64. (Budapest 1972)

Farkas, H.: Data to the knowledge of Eucypris sarsi and Erpetocypris obliqua (Crustacea: Ostracoda)

ANNALES HISTORICO-NATURALES MUSEI NATIONALIS HUNGARICI Tomus 64. 1972. Data to the Knowledge of Eucypris sarsi and Erpetocypris obliqua (Crustacea: Ostracoda) By H. FARKAS, Budapest Interest increased significantly in recent years in the Crustacea species described about the turn of the century. The cause lies in the fact that at that time the description of new species was set at a rapid pace, but in many instances the diagnoses and illustrations became quickly obsolete. The hardly or not at all identifiable species hindered the progress of the entire Crustacean systematics. All these hold good for the species Eucypris sarsi and Erpetocypris obliqua described by DADAY (1902) and it was these circumstances which instigated me to complement by some data our knowledge concerning these taxa. In his classical work, G. W. MÜLLER (1912) lists both species under the heading "Genera dubiae et species dubiae Cyprinarum", referring of course to the incompleteness of the description and illustrative material —or rather to MÜLLER'S doubts concerning their correctness. This apppears also in his citing by a question-mark DADAY'S description of the shell of Erpetocypris obliqua: "das vordere? schmaler als das hintere". The fact that these species are recorded in the list of "uncertain" forms even in the still single comprehensive work may serve as a basis for the systematist to disregard the species under discussion when describing new species. The type-specimens of both species are extant in the Collection of Crustacea of the Hungarian Natural History Museum, Budapest, and thus I had occasion to compare them with the specific descriptions. I could therefore convince myself that MÜLLER'S doubts concerning the correctness of the description were only partly justified. Thus DADAY had correctly relegated both species to their respective genera. In the possession of the complete s pecimens of Eucypris sarsi this became quickly and easily apparent, whereas in the case of Erpetocypris obliqua the control cannot be made with utter surety since only the shells and furcae of this latter species are available. However, both the shells and the furcae testify their correct assignment by DADAY to the genus Erpetocypris (Herpetocypris), The identity with practically one other genus and species may arise ; the shell strikingly resembles Amphicypris nobilis SARS (1901). The similarity of the two species is further enhanced by the •circumstance that they are both rather big: SARS gives 3.2 mm for the length of Amphicypris nobilis, while Erpetocypris obliqua is 4 mm long. Although the two data differ to some extent, they agree in being inordinately big for Ostracodes. The identity of the two species is contradicted, however, by the divergent character of their furcae: the furca bends downwards in SARS'S illustration, whereas it is straight in DADAY'S. On the other hand, the detailed description of the species is rather obsolete, and in parts even incorrect. DADAY writes as follows of the shell of Eucypris