768 ORDER HYPOTRICHA. 



here retained under the name of Amphisia gibha van crassa, has received from 

 Claparbde and Lachmann the title of Oxytricha crassa. 



Amphisia velox, Quenn. sp. 



Body elongate-lanceolate, about four times as long as broad, rounded at 

 the two extremities, the anterior end somewhat wider and curved slightly 

 towards the left ; the right border evenly arcuate, the left-hand one bulging 

 centrally in a gibbous manner; frontal styles uncinate, three in number; 

 ventral setae fine, forming three even median longitudinal rows ; a row 

 of similar sized marginal setae developed outside these on each side and 

 at some distance within the peripheral border ; five small, straight, slightly 

 projecting anal styles. Length 1-200". Hab. — Salt water. 



This species is described by Quennerstedt * under the name of Oxytricha velox. 



Amphisia pernix, Wrz. sp. Pl. XLIII. Fig. 12. 



Body extensile, highly flexible, much thickened, lancet-shaped, about 

 three times as long as broad, slightly narrower anteriorly ; peristome con- 

 tracted, extending obliquely backwards to the centre of the anterior third of 

 the body ; frontal styles entirely absent ; ventral setae minute, forming two 

 closely approximate central rows ; marginal setae equally minute, developed 

 on the ventral surface at a considerable distance from the periphery, and 

 presenting the appearance of two supplementary rows of ventral setae ; anal 

 styles five in number, disposed in an even oblique row, projecting for 

 nearly half their length beyond the posterior border; contractile vesicle 

 situated on the left-hand margin at a little distance behind the median line. 

 Length 1-230". Hab. — Salt water, Baltic Sea. 



Described by Wrzesniovvski t under the title of Oxytricha {Holosticha) pernix. 



Amphisia Kessleri, Wrz. sp. 



Body flexible and highly retractile, elongate-lanceolate, flattened, widest 

 centrally and narrowed towards the two extremities, nearly four times 

 as long as broad ; four uncinate frontal styles ; two median closely- 

 approximated rows of minute ventral setae ; marginal setae stationed at a 

 short distance only from the ventral series, to which they correspond in size 

 and character ; from twelve to fifteen anal styles, the five posterior only of 

 which present the characteristic sty late aspect and project beyond the pos- 

 terior border, the three more posterior of these five set further back than the 

 other two and curved slightly towards the right, the remaining seven to ten 

 minute and setose, forming a linear series between the left-hand marginal 

 and central ventral setae ; minute hispid setae, bordering the peripheral 

 margin of the anterior two-thirds of the body ; contractile vesicle situated 

 close to the centre of the left-hand lateral border. Length 1-160". 



Hab.— Salt water : Baltic Sea (Wrz.). 



* ' Sveriges Infusoriefauna,' Heft iii., 1869. 



t 'Zeitschrift fur Wissenschaftliche Zoologie,' Bd. xxix., 1877. 



