47 



So far as I have been able to consult the literature, the follow- 

 ing forms appear to be recorded for the first time in this country : 

 Gringa Uliformis, (also the first time since its discovery in Argen- 

 tina) Englena pisciformis, Phyllomitiis amylophagus, Blepharos- 

 ioma pigerrima and Gonostomuni pediculiforme. Tillina megas- 

 toma I have found abundant in the brackish waters of Lakes Pont- 

 chartrain and Borgne. 



NOTES ON SOME FORMS RARE AND OTHERWISE. 

 GRINGA FiLiFORMis Frenzel ('97). 



This is a rhizopod whose shape resembles that of a filiform 

 pseudopod of a Euglypha, leading an independent existence. It 

 is many times longer than wide and usually attenuated at one or 

 both extremities. Its mode of progression is peculiar, and, I be- 

 lieve, limited to itself. This takes place backwards or forwards in 

 a straight line, very slowly and without the emission of pseudo- 

 podia or any other disturbance of its shape, excepting an occa- 

 sional spirillum-like twist of its whole body. While moving in 

 this manner it bends its front extremity from side to side as if 

 seeking food. When it changes its course, it does so by emitting 

 from its apical extremity a pseudopod, which originates from a 

 cleft in this extremity and then resembles the beginning of long 

 fission. One segment of this cleft becomes a pseudopod, which 

 inclines to one side and indicates its direction of movement, while 

 the other segment remains intact and gradually slips down, so 

 to say, until it reaches the posterior extremity, where it disap- 

 pears. This whole process may also take place from the pos- 

 terior extremity. I have never seen the animal take food. Its 

 endoplasm is slightly granular throughout and contains three 

 sub-central and quite distinct contractile vacuoles as well as a 

 small round nucleus with a central nucleolus. This nucleus is 

 placed in the anterior fourth of the body and with the contractile 

 vacuoles show the same relative position as is usual with the 

 lobosa. This form was taken in abundance from the beach and 

 lived quite awhile in the moist chamber. The size varied from 30 

 to 50 microns in length and from 2 to 4 microns in width. 



This description agrees very closely with that of Frenzel ('97), 

 excepting in size and the presence of a nucleus, which he admits 

 he was unable to find, notwithstanding the employment of the 

 usual technic. I found no difficulty in supplying this deficiency, 

 as the nucleus was made exceedingly distinct (>^-in. obj.) after 



