684 ORDER PERITRICHA. 



crenated border, as delineated in the succeeding figure. The Vorticella plicata and 

 V. striata of De Fromentel, admitted by that authority to be probably varieties of 

 the same species, seem to be referable to the present type ; the transverse 

 striae are apparently coarser and more pronounced, and in this respect more closely 

 coincide with those of the marine Vorticella striata of Dujardin. By the last-named 

 investigator the animalcule now under discussion is figured and described under the 

 title of Vorticella infiisionum ; the cuticular striations are, however, misrepresented 

 as taking an oblique direction. 



Vorticella putrinum, Miill. 

 Pl. XXXIV. Figs. 23 and 24, and Pl. XLIX. Fig. 28. 



Body elongate, subfusiform, widest centrally and tapering towards each 

 extremity, the posterior region being most attenuate, from two to three 

 times as long as broad ; ovate, with a nipple-like anterior projection, when 

 contracted ; peristome-border constricted, scarcely everted ; the cuticular 

 surface finely striate transversely ; pedicle three or four times as long as 

 the body. Length 1-430" to 1-300". 



Hab, — Vegetable infusions in both salt and fresh water. 



The species, as above characterized, has been obtained abundantly by the 

 author in hay-infusions in both salt and fresh water, and is undoubtedly identical 

 with the form first associated with the foregoing title by O. F. Miiller, and figured by 

 him in his ' Zoologise Danics Prodromus,' in the year 1776. From Vorticella micro- 

 stoma, of which in fresh-water infusions it is a frequent companion, it may be readily 

 distinguished by the much more elongate contour of the body. An example in 

 which two smaller migrant zooids are being produced through a repetition of the 

 ordinary fissive act of a normal animalcule, is depicted at Pl. XXXV. Fig. 23a. 



Vorticella striata, Duj. 

 Pl. XXXIV. Figs. 15-19, and Pl. XLIX. Fig. 29. 



Body ovate or pyriform, about one and a half times as long as broad, 

 widest centrally, conically pointed posteriorly, constricted towards the border 

 of the peristome, which is narrow, not dilated, and measures one-half the 

 width of the centre of the body, the ciliary disc slightly prominent ; cuti- 

 cular surface conspicuously striate transversely ; pedicle slender, about 

 twice the length of the body. Length 1-850" to 1-600". 



Hab. — Salt water ; solitary or in scattered groups. 



This species, like Vorticella gracilis, is figured but not described by Dujardin, 

 an appended note indicating only its size and salt-water habitat. The present 

 author has recently, January 1879, obtained an animalcule corresponding with 

 Dujardin's type in all essential points, on the Jersey coast, finding it attached to 

 zoophytes and seaweeds freshly dredged from a depth of ten fathoms, off St. Aubin's 

 Bay. In size and general contour it very nearly resembles the V. microstoma of 

 stagnant pond water and infusions, but the transverse strise are coarser and more 

 conspicuous, and the body is much more retentive of its typical pyriform or urn- 

 like shape. Multiplication by longitudinal fission, and the reattachment of the 

 migrant zooid, as in the last-named form, was observed, the latter at the time 

 of, and anterior to, its separation from the parent stalk, assuming, as shown at 

 Pl. XXXIV. Fig. 16, a somewhat eccentric contour, the conical posterior extremity 

 being as it were invaginated, or thrust into the central body-portion. In one 

 example carefully followed, the migrant zooid occupied half an hour in wandering 



