426 ORDER FLAGELLATA-EUSTOMATA. 



indeed, seems almost to justify the transference of this specific type to the genus 

 Cryptomonas. The trichocyst-like structures are apparently confined entirely to 

 C.paramcEcium, and are probably associated with the symmetrically arranged granular 

 bodies just referred to. It has further to be remarked that the two do not occur 

 together, the present form being obtained mostly in ponds and standing water, and 

 the one previously described in artificial infusions. The sizes of the two animal- 

 cules are likewise too divergent to support the opinion of their identity. 



Chilomonas amygdalum, S. K. PL. XXIV. FIG. 49. 



Body elongate-ovate, almond-shaped, somewhat curved towards the 

 ventral aspect, from three to four times as long as broad ; flagella sub- 

 equal, exceeding the body in length ; endoplasm transparent, granular. 

 Length 1-2000". HAB. Salt water. 



This species was obtained abundantly by the author at St. Heliers, Jersey, in 

 November 1878, in the sea-water containing decaying sea-weed productive of Trinema 

 marina, previously described. Its movements when swimming are very active and 

 restless, mostly rotatory, the animalcules being further observed to chase and feed 

 voraciously, after the manner of Dinomonas, upon the vibrions and smaller monads 

 contained in the same water. When at rest it anchored itself by a spiral coil of the 

 posterior of the two flagella, as recorded of C.paramczcium. Multiplication by longi- 

 tudinal fission, similar to that which obtains in the last-named type, was frequently 

 witnessed. 



GENUS II. OXYRRHIS, Dujardin. 



Animalcules free-swimming, persistent in form, ovate or conical* 

 obliquely and unevenly emarginate or excavate anteriorly ; flagella two in 

 number, inserted close to each other within the frontal emargination, one 

 of them entirely vibratile, the other coiled spirally and used as an organ of 

 attachment during a state of quiescence, lashed to and fro and driving 

 the animalcule backwards through the water during natation ; oral aperture 

 situated in the frontal emargination close to the insertion of the flagellum ; 

 endoplasm transparent. Inhabiting sea water. 



There can be but little doubt that the Glyphidium marinum of Fresenius * and 

 Cohnf is genetically if not specifically identical with the species previously introduced 

 by Dujardin under the title of Oxyrrhis marina, and which earlier conferred generic 

 title, in accordance with the laws of zoological nomenclature, must necessarily take 

 precedence of the later one. The affinities of this generic type, in consequence of 

 the hitherto imperfect knowledge of its structural details, have not as yet been so 

 much as indicated, but from what is now known of this and other Flagellata, its 

 relationship to Chilomonas, last described, is clearly evident. Two species belong- 

 ing to that genus, C. paranuzaum and C. amygdalum, have been ascertained by the 

 author to present a closely corresponding coiled arrangement of the inferior flagellum; 

 while in both, the smaller notch-like anterior oral emargination may be regarded as 

 identical with the larger and asymmetrical one of Oxyrrhis. A chief difficulty 

 hitherto pertaining to the correct interpretation of this animalcule relates to the 

 inability of previous writers, Dujardin excepted, to recognize in the smooth rounded 

 extremity, the posterior region, and in the obliquely emarginate one the anterior 

 one, the true import of these being entirely masked in consequence of the remark- 



'Die Infusorien des Seewasseraquarium der Zoologische Garten, Frankfurt,' 1865. 

 t " Neue Infusorien in Seeaquarium," ' Zeitschrift fur Wissenschaftliche Zoologie,' Bd. 



xvi., 1866. 



