648 



SYSTEMATIC HISTORY OF THE INFUSORIA. 



It will be observed that Dujardin denies, as usual, the existence of an 

 anus ; this apertm-e is, however, generally stated to be found on the ventral 

 surface, near the posterior extremity. 



Plcescoxia PateUa= Euphtes Patella 

 (Ehr.). 



P. Vannm. — Depressed, oblong, oval; 

 very transparent, smooth, without strige, 

 5 to 8 anterior hooks ; and 7 to 8 straight 

 styles behind. In sea-water. 1-218". 



'p. (?) Scutum. — Larger than the pre- 

 ceding, with the band of vibratile cilia 

 extending further backwards, and the 

 posterior styles inflected and sinuous. 



^* This species," says Stein (p. 158), 

 " differs from the other Euplotes both in 

 having prehensile cilia (uncini ) not only 

 on the ventral surface, at the poste- 

 rior portion of the body, but also on the 

 dorsal surface, and in many other pecu- 

 liarities." 



P. halteata. — Oval, rather narrower in 

 front, diaphanous, with 5 striae (ribs); 

 the band of cilia extending five-sixths 

 the length of the body; styles few, feeble. 

 In sea- water ; no hooks, as in P. Vannm. 

 1-325". 



P. Cithara. — Oval, with ten regularly 

 disposed well-marked ribs ; the row of 

 cilia semicircular, extending two-thirds 



its length ; styles not long, and almost 

 confined to the posterior extremity. 

 In stagnant sea-water. 1-290" to 1-275". 

 P. crassa. — Oval, oblong; thick, but 

 diaphanous, with some faint signs of ribs ; 

 the band of cilia little curved, and ex- 

 tending one-half the length; 6 to 8 cm-ved 



styles at anterior, and 5 to 7 straight 

 ones at posterior extremity. With the 

 preceding, in sea-water. 1-362". 



P. CJiaron. — In-egularly oval, truncate 

 in front, narrower behind, ^dth well- 

 marked irregular ribs; styles long, not 

 curved. Differs much from Euplotes 

 Charon (Ehr.). 



P. affinis. — Differs from P. Charon, by 

 its habitat being in fresh water, and by 

 having its anterior portion narrower, 

 whilst its posterior is more rounded and 

 less plaited. 



P (?) subrottmda. — Oval, thick, gra- 

 nular within ; no distinct ribs ; truncated 

 and fissured in front ; styles long, thin at 

 each end. In infusions. 1-535" to 

 1-475". 



Perty found it mider the ice in a pond 

 near the Hospice of St. Bernard, and sug- 

 gests it to be no more than a variety of 

 P. affinis with indistinct ribs (strice). 



P. (?) radiosa. — Longer than the pre- 

 ceding, 1-520" to 1-395'*", ^\dth long styles 

 radiating from each extremity. In river- 

 water. 



P. longiremis. — Very depressed, irre- 

 gularly oval, dilated on the side support- 

 ing the cilia, where it is more transpa- 

 rent, with 3 to 4 slightly prominent large 

 ribs ; stvles numerous, verv long and 

 flexible.' In sea- water. 1-400" to 1-306". 



P. aculeata = Euplotes aculeatus (Ehv.). 



Genus DIOPHRYS (Duj.) (XXYL 22 a, 6).— Body discoid, irregular, 

 thick ; concave on one side, convex on the other ; with long styles grouped 

 at each end ; no mouth. 



DiOPHRYs marina (xxvi. 22 a, b). — 

 Oval, with a longitudinal excavation; 

 terminated in front by 5 great vibratile 



cilia, and behind by 4 to 5 very long geni- 

 culate styles. In sea- water. 1-580". 



Genus COCCUDINA (Duj.) (XXYI. 30 a, &, c). — Body oval, depressed 

 or nearly discoid, often rather sinuous on the margin; convex, pitted or 

 granular, and glabrous above ; concave below, with vibratile cilia, and styles 

 or hooks, ser\'ing as feet ; without mouth. 



Intermediate between Lo.vodes and Plcesconia, having the appendages of 

 the latter, and the general figiu^e of the former. Ehrenberg has left the 

 Coccudince known to him dispersed among the species of Oxytricha and 

 Euplotes. Aspidisca should probably be referred to this genus. 



vibratUe. In marsh-water and swampy 

 ponds. 1-965". 



C. crassa. — Oval; larger and appa- 

 rently truncated behind ; contracted and 

 sinuous in front; convex above, with 

 feeblv-marked ribs ; anterior appendages 



CoccuDiNA costata. — Oval, obliquely 

 contracted, and sinuous in front ; convex 

 and furrowed beneath, where from 5 to 6 

 very prominent tubercular ribs are found, 

 supporting longcilia : appendages grouped 

 at each end ; the anterior thinner and 



