1885.] 



MICROSCOPICAL JOURNAL. 



123 



easily recognized as a member of the 

 genus actin6monas by this peculiar 

 and characteristic shivering. When 

 quietly seated at the extremity of the 

 short temporarily developed pedicel, 

 the flagellum dashes the food-particles 

 into contact with the pseudopodia, 

 which then draw it into the body, 

 a performance characteristic of the 

 genus. 



The pseudopodia themselves are 

 usually simple and often tipped by a 

 minute spherule of protoplasm, with 

 one or more protoplasmic enlarge- 

 ments in the course of the ray, and a 

 frequent thickening at any point by a 

 flow of sarcode, after the manner of 

 the rhizopoda. The branching, in 

 the individuals obsei"ved, wasat times 

 a simple bifurcation, occasionally be- 

 coming compound as shown in the 

 figure. 



The small contractile vesicles are 

 scattered near the periphery, their 

 exact number being difficult to deter- 

 mine on account of their irregular 

 distribution and apparently diflerent 

 distances from the surface under ex- 

 amination. At least six can be de- 

 tected, two placed near the frontal 

 border, two on the opposite side near 

 the equator, and two in the posterior 

 part of the body. This large number 

 would be sufficient to distinguish the 

 creature from the previously observed 

 species, all of which are marine, did 

 not the branching pseudopodia serve 

 the purpose better, as this habit has 

 not been noticed in the salt-water 

 forms. 



The thread-like pedicel seems to be 

 but seldom protruded unless, in the 

 instances in which I have failed to ob- 

 serve it, the infusorian has been in 

 such a position that the body has ob- 

 scured it. Two or more of the 

 pseudopodia appear to serve as an- 

 choring attachments, the capitate 

 tips being applied to an algal or other 

 filament. This habit has also been 

 noticed in A. pusilla^ S. K, 



As the infusorian was first obtained 

 in early spring, or what by courtesy 

 toward our abominable winter cli- 



mate is so styled, the fact suggested 

 the specific name. 



Bicosceca dissiniilis, sp. nov. (Fig. 



2.) 



Lorica elongate-ovate, two and one- 

 half times as long as broad, slightly 

 narrowed anteriorly and there form- 

 ing an inconspicuous, neck-like pro- 

 longation, the border truncate, not 

 everted ; supported posteriorly on a 

 pedicel nearly equalling it in height ; 

 enclosed body subspherical, situated 

 near the centre of the lorica, not in 

 contact with the walls when extended, 

 nor projecting beyond the frontal 

 border ; contractile ligament about 

 one-half as long as the lorica ; nucleus 

 spherical, subcentral ; contractile ves- 

 icle double, postero-terminal. Length 

 of lorica, ^^^ inch ; diameter of en- 

 closed animalcule, ^-i^-^ inch. Habi- 

 tat. — On Utric7ilaria from the pine 

 barrens of New Jersey. Solitary. 



There is a remarkable disparity 

 between the size of the infusorian's 

 body and that of the sheath formed 

 for its protection. It is a pigmy in a 

 giant's castle, and it seems a timid 

 creature. Safely surrounded by its 

 transparent walls, it remains near the 

 centre of the single apartment even 

 when the retractile ligament has ex- 

 tended to its greatest length, never 

 passing the anterior opening, never 

 exposing itself to any current except 

 that made by the lashing of its own 

 flagella, the body freely floating at 

 the extremity of the restraining thread. 

 The lip is short and inconspicuous, 

 and the frontal excavation shallow. 

 The long flagellum is very long, and 

 seems to vibrate throughout its entire 

 length. It at least does not present 

 the aspect of a lash curved and vi- 

 brating at the distal extremity only, 

 as in most of the forms hitherto dis- 

 covered. The lorica also is the 

 largest yet noted in any member of 

 the genus, while the enclosed zooid 

 is among the smallest. 



Bicosceca acumtndta, sp. nov. 



(Fig. 3.) 



Lorica irregularly ovate, less than 

 twice as long as broad, slightly nar- 



