GENUS HOPLITOPHRYA. 571 



the first-named species in the contour of the sucker, which is horseshoe-shaped, or 

 presents the aspect merely of an oval depression armed with very strong cilia. The 

 cuticular surface is further destitute of the longitudinal striations that form so con- 

 spicuous a feature in H. gigantea. The title of Haptophrya tritonis is proposed by 

 M. Certes for the distinction of this apparent new species. 



The animalcule described by Dr. E. Evarts * under the name of Opalina disco- 

 glossi, and obtained by him at Naples from the intestine of Discoglossus pictus, is 

 evidently referable to the genus Haptophrya. While differing somewhat in general 

 form from H. gigantea, it agrees with that species in size, in its possession of a 

 sucking-disc, single endoplast, and canal-like contractile vesicle, as also in the 

 phenomena of reproduction. 



GENUS IV. HOPLITOPHRYA, Stein. 



Animalcules mouthless, ovate or elongate, entirely ciliate, developing on 

 the ventral surface, towards the anterior extremity, a corneous, keel-like 

 band or one or more horny hooks, by which they are enabled to attach 

 themselves to the intestinal wall of their selected host ; endoplast and 

 contractile vesicle conspicuously developed. Entirely endoparasitic. 



Hoplitophrya lumbrici, Duj. sp. PL. XXVI. FIG. 15. 



Body elongate-ovate, somewhat flattened ; armature consisting of a 

 single bifid, horny hook, which is developed on the ventral surface near the 

 anterior extremity; endoplast band-like, axial, extending through nearly 

 the entire length of the body; contractile vesicles numerous, spherical, 

 forming an irregular line along each lateral border. Length 1-144" to 

 1-108". Dividing by sub-even transverse fission. 



HAB. Intestine of the common earth-worm, Lumbricus terrestris. 



Stein has proposed to confer upon this animalcule the title of Hoplitophrya 

 armata, but since he himself acknowledges its identity with the previously described 

 Opalina lumbrid of Dujardin, it is desirable that the earlier applied specific name 

 should be retained. It would, as suggested by Stein, seem to be by no means 

 improbable that the Anoplophrya (Leucophrys) striata of Dujardin, tenanting the same 

 host, represents an immature condition only of the present type. 



Hoplitophrya uncinata, Schultze sp. 



Body ovoid, ventral uncini two in number of unequal length, developed 

 one on each side of the median line, towards the anterior extremity of the 

 body ; contractile vesicle elongate, canal-like ; endoplast band-like, axial. 

 Length 1-120". Inhabiting various marine Planarians. 



According to Max Schultze this animalcule, first described by him under the 

 title of Opalina uncinata, inhabits only Planaria ulvce : it has more recently, however, 

 been found by Claparede and Lachmann abundantly infesting a member of the genus 

 Proceros. 



Hoplitophrya falcifera, Stein. 



Body slightly flattened, sometimes shortly ovate, sometimes triangular, 

 widest posteriorly, the length rarely exceeding the greatest breadth ; 



* ' Tijds. nederl. dierk. Vereeniging,' Bd. iv., 1879. 



