3 1 6 ORDER FLA GELLA TA-PANTOSTOMA TA. 



The genus Chloraster, as 'here recognized, includes, in addition to the Chloraster 

 gyrans of Ehrenberg, the Pyramimonas of Schmarda, and a third salt-water form 

 recently obtained by the author in the Channel Islands. The close affinity of all 

 three, and the undesirability of separating them into two generic groups, is made 

 manifest on reference to the figures of both Ehrenberg's and Schmarda's types, as 

 included in Stein's recently published work, and reproduced at PL XIX. As 

 previously intimated, it has been proposed by Diesing and Biitschli to relegate the 

 representatives of the genus Tetramitus also to that of Chloraster, or rather to Pyra- 

 mimonas as defined by Schmarda, but it is evident from the comparatively complete 

 data now made known concerning these respective groups that they exhibit nothing 

 in common with each other, and cannot consistently be united. 



Chloraster gyrans, Ehr. PL. XIX. FIGS. 21 AND 22. 



Body subfusiform, widest centrally, pointed at each extremity, about 

 twice as long as broad ; the central region sometimes produced into 

 four symmetrical lobate processes, which stand out at right angles to the 

 long axis of the body ; flagella five in number, of equal length, produced 

 from the pointed anterior extremity ; endoplasm green, enclosing anteriorly 

 an eye -like pigment-speck. Length 1-632". HAB. Fresh water. 



The delineations of this type are reproduced from the figures given in Stein's 

 recently published volume.* 



Chloraster tetrarhynchus, Schmarda sp. PL. XIX. FIG. 20. 



Body pyramidal or conical, truncate and widest anteriorly, the opposite 

 extremity more or less pointed, longitudinally carinate down the central 

 line at each of the four lateral angles ; four long, recurved, setose flagella 

 issuing from a papilla-like prominence in the centre of the anterior border, 

 a long vibratile flagellum projecting from the centre of the reflected seta ; 

 colour green ; movements swift, in a straight line or rotatory. Length 

 1-780" to 1-720". HAB. Fresh water : near Vienna (Schmarda). 



No indication is given by Schmarda, in either his drawings or description, of the 

 central vibratile flagellum characteristic of both the preceding and the succeeding 

 species ; this organ is, however, so difficult to detect without the use of reagents 

 and the most perfect magnifying glasses that it may have naturally escaped his 

 attention. In some instances, as likewise in the case of C. agilis, the more normal 

 quadrate contour of the body of the animalcule is exchanged for a rounded sub- 

 conical or shortly fusiform outline. No coloured eye-like pigment-spot appears 

 to be present in this type. Mr. Carter, in a manuscript note-book kindly placed 

 at the author's disposal, has figured an organism with four radiating seta-like 

 appendages at the anterior extremity, obtained by him from a well at Bombay, that 

 is apparently closely allied to if not identical with this species. It having been 

 collected in company with Cladophora fracta, Mr. Carter has suggested, in absence 

 of further evidence, that the form may represent the motile zoospore-like elements 

 of that algal ; the appearance of both this and the following form, indeed, so closely 

 approximates such reproductive structures, that but for the characteristic and 

 evidently independent movements exhibited by C. agilis, circumstances would have 

 apparently justified the relegation of this genus to the vegetable series. 



In the accompanying figure given of this species, reproduced from Stein, there 



' Infusionsthiere,' Abth. iii., 1878. 



