GENUS CO LA CI UM. 393 



Coelomonas grandis, Ehr. sp. Pl. XX. Fig. 59. 



Body highly contractile and variable in form, regularly or irregularly 

 elongate-ovate or subspheroidal, pharyngeal dilatation occupying nearly 

 the entire anterior half of the body ; flagellum short, not equalling the 

 body in length ; cuticular layer enclosing innumerable golden-green 

 chlorophyll-granules ; contractile vesicle single, anteriorly situated ; endo- 

 plast spheroidal, subcentral. Length 1-430". 



Hab. — Mar.sh water ; movements sluggish. 



This species, as previously intimated, is identical with the Monas grandis of 

 Ehrenberg. 



Genus VIII. ASCOGLENA, Stein. 



Animalcules solitary, monoflagellate, highly elastic and changeable in 

 shape, enclosed within a sessile tubular or flask-shaped lorica, to the bottom 

 of which they adhere by the posterior extremity ; endoplasm coloured 

 green, enclosing an anterior eye-like pigment-spot ; oral aperture and 

 contractile vesicle as in Euglena. Inhabiting fresh water. 



The representatives of this genus may be described as Eiigknce which secrete 

 and inhabit sessilely attached loricse and hold in their family group a position 

 corresponding with that occupied by Vaginicola as compared witli Vorticclla among 

 the Vorticellida3, or that of Salpingieca with relation to Alonosiga among the Choano- 

 Flagellata. 



Ascoglena vaginicola, Stein. Pl. XXI. Figs. 28 and 29. 



Lorica erect, tubular, subcylindrical, rounded and widest posteriorly, 

 tapering gradually towards the anterior aperture, about three times as long 

 as broad, its consistence finely granular with a somewhat more transparent 

 anterior border ; animalcule clearly visible through the walls of the lorica, 

 Euglena-like and highly contractile, its distal extremity when extended 

 reaching to the anterior aperture ; dividing within the lorica by transverse 

 fission. Height of lorica 1-640". Hab. — Fresh water. 



Genus IX. COLACIUM, Ehrenberg. 



Animalcules monoflagellate, exhibiting two distinct phases of existence, 

 the one free-swimming and the other sedentary : in the motile stage solitary, 

 highly elastic and changeable in form, and in all essential details corre- 

 sponding with simple free-swimming Euglcnce ; in the sedentary stage afiixed 

 socially, mouth downwards, to a simple stalk or to the extremities of a more 

 or less elevated branching pedicle or zoodendrium, which is produced by 

 the repeated longitudinal fission of a single primary zooid ; endoplasm 

 coloured green, enclosing an anterior eye-like pigment-spot ; oral system, 

 endoplast, and contractile vesicle, as in Euglena. Inhabiting fresh water. 



The several species referred to the genus Colacium, as originally instituted by 

 Ehrenberg, are not represented as possessing any distinct flagelliform appendage, 

 though the presence of one or more such organs was suspected by him through the 



