416 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ment. Longer and more compactly arranged cilia are found in the region 

 of the mouth, and seem to have their function limited to j^roducing an 

 alimentary current. A. lacazei seems to be most nearly allied to A. 

 margaritifer, and to have some resemblance to A. cygnus. A. massiliensis 

 varies in size, and moves not only by the aid of its cilia, but also by the 

 successive contraction and dilatation of the whole mass ; sometimes it may 

 be seen to twist on itself. LoxojjJiyllum pyriforme sp. n. has a great power 

 of contraction, and is incessantly changing its form; the cilia do not 

 appear to be regularly distributed, though the trichocysts, which are found 

 all over the body, are so ; the endoplast appears to consist of two oval 

 nuclei, of some size, very granular, and without nucleoli. Lemhadion ovale, 

 another new species, differs from the only species of the genus yet definitely 

 described by having only one caudal seta, by the elongated form of its buccal 

 pit, the elongation of its vibratile membrane, and other characters. After 

 an account of Plagiopyla nasuta var. marina, and Cyclidium glaucoma, 

 Lemhus intermedius is described ; it is very agile and extensile, but, on the 

 least pressure, divides into two, a little behind the mouth. 



(2) Heterotrichous Infusoria. — Metopus sigmoides is recorded, and a long 

 account is given of Condylostoma patens, as to which previous writers have 

 been in some disagreement, and a revised synonymy of the species is 

 offered. 



(3) Peritriclwus Infusoria. — Mesodinium pulex, and Gyrocoris oxyura are 

 described, as well as Vorticella nehulifera ; of this last genus there are 

 also two new species : V. plicata, distinguished by its longitudinal folds, 

 and V. anomala which is remarkable for the delicacy of its anterior end, 

 and the elongate cylindrical form of its pharynx ; the contractile vesicle is 

 very large ; the stalk differs from that of most members of the genus in 

 being contractile in its anterior half only ; this is made up of a fine un- 

 ornamented cuticle, a hyaline peripheral zone, a thick contractile sarcolemma, 

 and a slender central cylinder. The lower half of the stalk has the cuticle 

 thicker ; this new form is interesting as being intermediate between the 

 Vorticellidfe with a contractile, and those with a rigid peduncle. It is 

 very rare. Of Zoothamnium two species were found, of which Z. alternans 

 was described by Claparede and Lachmann, and Z. plicatum, which is new, 

 and is distinguished from Z. marinum by having the stalk jointed, and by 

 the possession of longitudinal striae on the cuticle. Epistylis harhata is a 

 new and very common species ; it is perfectly smooth externally, and has 

 an elevated vibratile disc; it contains parasitic cysts of, apparently, an 

 Opalina; this small infusorian introduces itself by the peristome, and 

 passes into the parenchyma, living at the expense of its host which it com- 

 pletely destroys. When set free the cyst swims about rapidly and under- 

 goes a number of modifications. Gotlmrnia fusiformis sp. n. is very closely 

 allied to C. nodosa; G. striata sp. n. differs from G. ptisilla by the size of 

 the body, the presence of cuticular annellations, the absence of an opercu- 

 lum, and the shoitnessof the peduncle. 



(4) Hypotriclious Infusoria. — Ghilodon complanatus sp. n. is continually 

 changing its form, and has a distinct ventral surface very different from the 

 dorsal ; the mouth is laige, the pharynx short, conical, and provided with 

 chitinous rods, which form a framework for it ; it has no vibratile lip, as in 

 G. cucullulus, in the company of which it is found living, ^gyria angustata 

 with a variety, ovalis, is next described ; ^. marioni is a new species, and 

 is marked by the reduction of the frontal and ventral cilia, the presence of 

 a spiny crest on the left valve, the longitudinal strise in the dorsal region, 

 ami the form of its swallowing apparatus. M. monostyla, ^. fiuviatilis 

 (var. n. marina), Aspidisca polystyla (var. n. maxima) are next noticed; 



