82 D. BRYCE ON A NEW CLASSIFICATION OF THE BDELLOID ROTIFERA. 



all the identifications which I hav^e seen of this elusiv^e species. 

 It has first to be noted that, although Ehrenberg mentions it 

 both in 1830 (2) and in 1831 (3), the few particulars he gives 

 (on the latter occasion) may be taken as superseded by those 

 given in 1838 (4), since in the interval he had found the species 

 on two occasions (but from the same locality as the original 

 capture). Further, that his description of the genus Callidina 

 was based on this one species only, as the second known to him 

 Callidina rediviva^ also mentioned in the same work (4) was 

 only found about the time when the proof-sheets were already 

 under revision. Thus the identity of C. elegans is to be judged 

 not only from the specific description, but also from the descrip- 

 tion of the genus Callidina, wherein particulars are given which 

 liave much importance. Collating both descriptions, it is to be 

 gathered that C. elec/ans of Ehrenberg was a blind Philodine, 

 oviparous and spindle-shaped, having a stout ciliated rostrum 

 and a long-extending foot with tw^o spurs and four toes : a corona 

 of two small discs, not mounted on pedicels ; rami with many very 

 fine teeth ; stomach thread-like ; antenna short ; with some re- 

 semblance to Philodina erytkrophthalma, but with spurs somewhat 

 longer than in that species yet shorter than in P. macrostyla, 

 and with very short terminal toes. Some seven figures are given 

 to supplement this description, and are principally noteworthy 

 for the curious presentment of the corona, which gives some 

 ground for Milne's (18) interpretation of it as of the Adineta 

 type, and which certainly gives no clear suggestion of any form 

 of corona known to me. 



The description of the stomach as thread-like (" fadenartig ") 

 in the generic description is to be understood as referring to 

 C. elegans. In the description of C . rediviva, interj^olated at the 

 time of proof-revision, Ehrenberg notes as a conspicuous mark 

 the breadth of the food-canal, apparently meaning the lumen of 

 the stomach, and he speaks of the stomach-structure as resembling 

 that of P. collaris. It is clear from the further details given 

 that both P. collaris and C. rediviva had stomachs with a wide 

 lumen, and that both were pellet-makers. That such is the case 

 with C. rediviva gives the more weight to the description of the 

 stomach in C. elegans as thread-like. 



If one may rely on the various details given by Ehrenberg, 

 his C. elegans diflTers in several respects from that described by 



