662 ORDER PERITRICHA. 



turn, according to Stein, in 5. gemmipara being homologous with the peristome 

 proper. As in S. tintinnabulum this organ is less complex than in either of the pre- 

 ceding species, the partial retention by the peristome of its tj-pical character, as found 

 to exist, might be anticipated. Although the funnel is less convolute in this t)-pe, 

 the character it imparts to its general aspect is none the less conspicuous, its height, 

 one-half that of the body, being indeed greater relatively than in either of the 

 preceding forms. The examples supplying the figures and description of this 

 new species were originally met with by the author scattered sparingly over the 

 whole surface of the integument of a young newt measuring about one inch in length, 

 taken from a pond at Stoke Newington, London, in August 187 1. Those stationed 

 on the delicate ramifications of the branchial appendages were found to be especially 

 suitable for examination, a portion of one of these organs bearing several being 

 removed and subjected to a magnif)'ing power of 800 diameters. The external 

 surface of the cuticle in this species appears to be less firm than in S. gemmipara 

 and Scheiiiaui, the peristome contracting over the mouth and giving the anterior 

 margin a rounded contour on the withdrawal of the funnel. The wTeath of cilia 

 springing from the base of the funnel are very long and powerful ; a distinct pedicle 

 could not be detected in any instance, but simply a sucker-Uke disc of adherence, as 

 shown by Hertwig to occur in S. gemmipara. Still more recently, July 1878, the 

 author has obtained this species attached to young newts collected in the neighbour- 

 hood of St Heliers, Jersey, and was in this instance fortunate enough to obser\'e 

 examples undergoing the process of multiplication by transverse fission. In such a 

 case the membranous funnel and peristome were retracted, and a circlet of long, 

 powerful cilia developed round the centre of the body, as shown at PI. XXXIII. 

 Fig. 41 ; the anterior portion with this circlet of cilia became detached and swam oflf 

 like a free Voriicdla, while the remaining moiety shortly developed a new peristome 

 and spiral membrane, presenting in its half-matured state the aspect given in 

 Fig. 42 of the same plate. The elongate, band-like endoplast was obsened in one 

 instance to share in the process of division. Excepting in Ophrydium, division by 

 transverse fission has not as yet been recorded of any other representative of the 

 present family group. 



Further evidence of the cosmopolitan distribution of Spirochona tintinnabulum is 

 afforded by the recent receipt of specimens attached to the same specific host, 

 tlirough Mr. John Hood, from the neighbourhood of Dundee. 



Genus IV. STYLOCHONA, S. K. 

 (Greek, stulos, stem ; chone, funnel.) 



Animalcules solitarj^ ovate or elongate, mounted on a distinct rigid 

 pedicle ; peristome differentiated as in the genus Spirochona, forming a more 

 or less convolute, funnel-shaped, membraniform expansion. 



This genus is here instituted for the receprion of two marine types which 

 differ from Spirochona in their possession of distinctly developed, rigid pedicles. Until 

 quite recently such a structure was supposed to be rudimentarily represented 

 in the last-named genus. It has, however, been recently shown by Hertwig 

 of 5. gemmipara that such element is there replaced by a somewhat complex 

 acetabuliform organ of adherence. 



Stylochona nebalina, S. K. Pl. XXXIII. Figs. 56 and 57. 



Body elongate, obconical, tapering posteriorly, widest at the anterior 

 margin, attached by a slender rigid footstalk, often equal in length to one- 

 third of the entire body ; membranous funnel contracted at its base, 

 describing little more than a single spiral turn, its terminal border slightly 



