774 ORDER HYPOTRICHA. 



by the Swiss authorities. Thus, while they have described the central ventral surface 

 as entirely covered with oblique rows of short setae, no definite number of rows is 

 mentioned, and in their illustrations they are entirely left out, an omission which 

 also applies to the marginal setal series of the same region. The position of the 

 contractile vesicle as given by Claparede and Lachmann is also at variance with 

 Stein's description, the first-named investigators describing and delineating it as 

 situated at the posterior end of the central division of the body, while Stein 

 declares it to occupy that position near the termination of the peristome common to 

 the majority of the Oxytrichidae. 



Epidintes auricularis has been recently met with in tolerable abundance by 

 Mereschkowsky among algae in the White Sea. According to this observer,* no 

 less than five or six oblique rows of fine setae are distributed upon the ligulate 

 anterior prolongation, nine similar rows upon the central or ventral region, and five 

 parallel rows upon the posterior or caudal prolongation. The marginal series on 

 either side towards the anterior extremity are represented by Mereschkowsky, 

 as shown at PI. XLIII. Fig. 30, as taking the form of minute, immotile, bead-like, 

 or columnar prominences. 



Epidintes retractilis, C. & L. sp. PL. XLIII. FIGS. 23 AND 24. 



Body elongate, about five times as long as broad, the central portion 

 much inflated, shortly and broadly fusiform, the anterior region very narrow, 

 its width equal to one-quarter only of that of the centre part, and about one- 

 half its length, the posterior or tail-like prolongation ligulate, still narrower 

 than the anterior one, nearly equal in length to the conjoined preceding por- 

 tions, highly contractile, and capable of being almost entirely withdrawn into 

 the more inflated central region ; three nearly straight rows of setae developed 

 on the anterior part of the ventral surface, those of the central region 

 numerous, but their actual number and arrangement undetermined ; two 

 central straight rows developed upon the caudal portion in addition to a 

 marginal set on each side ; four terminal projecting anal setae. Length 

 when extended 1-150". 



HAB. Salt water : Norwegian coast (C. & L.). 



This animalcule is identical with the Oxytricha retractilis of Claparede and Lach- 

 mann. While the details of the ventral setae, as given by its discoverers, are not 

 quite so explicit as might be desired, it is evident that we have here a type closely 

 allied to Epidintes auricularis, and with which Stein has considered himself justified 

 in associating it. The remarkable retractile character of the attenuate caudal 

 extremity, together with the wider expansion of the central part, serve to distinguish 

 it specifically from the last-named form. 



Epiclintes radiosa, Quenn. sp. PL. XLIII. FIGS. 31 AND 32. 



Body elongate, about five times as long as broad, central and anterior 

 portion compressed fusiform, slightly narrowed anteriorly and bearing at its 

 summit five very large, straight, radiating frontal styles, the posterior or 

 caudal prolongation narrow or linear, exceeding the entire anterior region in 

 length ; a single row of marginal setae developed upon each side of the 

 fusiform anterior and central portions, and a double row of similar setae 



* "Protozoan des nordlichen Russland," ' Archiv fur Mikroskopische Anatomic,' Bd. xvi., 

 1878. 



