652 ORDER PERITRICHA . 



This species, as originally described by Cohn,* was met with in considerable 

 abundance on and among the dorsal papillae of a small deep-water Nudibranch, 

 apparently Doris muricata. A species of Trichodina referred to but not described 

 by Moebius and Meyer in their ' Fauna of Kiel,' as occurring on another Nudibranch, 

 JEolis alba, is probably also identical with this type. 



Licnophora Cohnii, Clap. PL. XXXIII. FIG. 25. 



Body proper or capitulum more orbicular than in the preceding species, 

 joined to the suctorial foot by a slightly compressed and usually more 

 attenuate pedicle ; peristomal ciliary wreath of relatively larger size than in 

 L. Auerbachii, describing an almost circular spire, its cilia very long and 

 slender^ Length 1-500" to 1-400". 



HAB. Salt water, on the branchiae of the Annelid Psyrmobranchus 

 protensus. 



Fam. VII. OPHRYOSCOLECID^E, Stein. 



Animalcules free-swimming, ovate or elongate, soft or encuirassed, pos- 

 sessing a peristome and protrusible ciliary disc as in the Vorticellidae ; one 

 or more style-like caudal appendages usually developed at the posterior 

 extremity ; anal aperture postero-terminal or opening into the vestibulum 

 or oral fossa. 



As originated by Stein, this family group includes only the two endoparasitic 

 genera Ophryoscolex and Entodinium, animalcules which have up to the present time 

 been examined by no other special student of the Infusoria, and are but briefly 

 described by him, without illustration, in the year 1858.! There can be but little 

 doubt, however, that Stein's types include the infusorial forms reported by MM. Gruby 

 and Delafond,| as inhabiting in prodigious numbers the first and second stomachs 

 rumen and reticulum of various ruminants, the majority of these animalcules 

 being encuirassed and comparable in aspect to Rotifera. One species, more espe- 

 cially, represented by them as having a long, flattened body and projecting tail, 

 with a convex dorsal and plane ventral surface, indented posteriorly, and a girdle 

 of cilia round the centre of the body, length i-ioo", is apparently identical with 

 Stein's Ophryoscolex Purkynjei, while another, described as closely resembling the 

 Rotifer Brachionus polyacanthus of Ehrenberg, is probably the Entodinium dentatum 

 of the same writer. The numbers of these animalcules found by the French savants 

 infesting the indicated viscera of the sheep are something astounding. In five 

 centigrammes of alimentary matter taken from the two first stomachs of this rumi- 

 nant it was ascertained that no less than one-fifth of this total weight was composed 

 of the bodies of these organisms. In the third and fourth stomach psalterium and 

 abomasum of the same animal only dead or empty carapaces were to be found, the 

 softer and nutrient parenchyma having apparently been digested. From these 

 facts MM. Gruby and Delafond argue that the food-supply of ruminants, though 

 ostensibly of a purely vegetable nature, consists to a very considerable extent of 

 microscopic animal organisms, which develop freely and with great rapidity in the 

 first and second stomachs of their associated host, but are killed and assimilated on 

 passing into the third and fourth. Like results were obtained by them on examining 

 the viscera of a horse, for while found living in vast numbers in the cascum and 

 dilated colon, dead and empty carapaces were alone encountered in connection 

 with the contracted colon and rectum. It was found possible to preserve these 



* " Neue Infusorien im Seeaquarium," 'Zeit. Wiss. Zool.,' Bd. xvi., 1866. 

 t ' Abhandlungen d. Konigl. Bohmischen Gesellschaft d. Wiss.,' Bd. x. p. 69. 

 j 'Comptes Rendus,' Dec. 1843. 



