OF THE CKUSTACEAN GEI^^TJS BATHT]S"ELLA. 339' 



By the great kindness of Prof. Yejdovskj I have been enabled 

 to make a re-examination of the unique existing specimen of 

 BatTiynella, which he has sent to me for the purpose. The 

 specimeo, which is mounted as a microscopic preparation in Canada 

 balsam, is, unfortunately, not in a good state of preservation, 

 being much shrivelled and lacking the greater part of antennules 

 and antennae as well as part of the uropods. The following- 

 account is taken from Prof. Vejdovsky's description, supplemented 

 in one or two points from my own observations. 



Bathynella (PI. 20. fig. 1) is described by Prof. Vejdovsky as 

 resembling in general appearance the minute copepods of the 

 genus CantJiocainptus. The body is, in the present state of the 

 specimen, about "75 mm. long *, and consists, according to the 

 original account, of (1) a cephalic region bearing two pairs of 

 antennse, mandibles, and at least two more pairs of mouth- 

 appendages ; (2) a thoracic region of seven free somites each 

 bearing a pair of biramous appendages ; and (3) an abdomen of 

 six somites, of which the first and second bear small appendages 

 while the last carries two pairs of caudal plates. It appeared to 

 me, on examining the original specimen, that there were indi- 

 cations of an additional somite in the abdominal region, and ou 

 mentioning my belief to Prof. Yejdovsky, he informed me that 

 lie had actually seen this somite in the living animal and sent 

 me one of his sketches in which it was plainly figured. The 

 presence of this somite, as Prof. Yejdovsky himself remarked in 

 sending me the sketch, is very important for the settlement of 

 the systematic position of the animal, for it enables us to readjust 

 the delimitation of the regions of the trunk in such a way as 

 to bring their segmentation into precise accord with the normal 

 arrangement for the Malacostraca. 



Prof. Yejdovsky implicitly referred the segmentation of the 

 body to the type characteristic of the Arthrostraca, in which 

 the first thoracic somite, bearing the maxillipeds, is fused with the 

 head. "Were this the case we ought to find four pairs of buccal 



1898, xiv. 2 pp.). The author informs me that he has there expressed the 

 opinion " das Bathynella eine besondere Stelle zwischen den Arthrostraken 

 einnehmen diirfte, und vielleicht eine neue Ordnung ' Pleopodophora, ' repril- 

 sentirt." 



* Vejdovsky gives the total length as about 1 mm. 



