NOTES OX THE GENUS LEP'l'OI'Iim S 



WILLIAM A. KEPXER 



In the year ]S(\{) llrrtwiir and Lesser published in the Archir 

 fiir mikro.<i/:i)])i.schr Aiuifm/n'f (Supplement zu Banden an arti- 

 cle entitled " Uel)er Riiizopoden und denselhen naluvsteliendc 

 Organismen." On page 57 of this volume tliev dcscri'ot' a new- 

 genus which they name Leptophrys. The following is their diag- 

 nostic description of this genus: "Body variable in form, sheet- 

 like with processes put out, pointed and unbranched psendopodia, 

 which are chiefly found at the end of the processes; the paren- 

 chyma is filled with small non-contractile vacuoles nearly ecjual 

 in size"; and though they saw but three bodies in a single indi- 

 vidual which they took to be nuclei and failed to see nuclei in any 

 other specimens, they add: "Nuclei in great number." The color 

 or its absence in the "pearl-like" granules served them as a basis 

 for distinguishing the two species, L. cinerea and L. clegans. 



In December, 1904, I discovered in some water taken l)y Mr. 

 AVilliam G. Lapham from an oozy bank near Afton, ^'irginia. a 

 large Vampyrella-like specimen (Fig. 1), which except for the ab- 

 sence of nuclei and the variable si/e of the vacuoles answered in 

 <letail to Lrp1op}m,.s vleqans. In size the creature would cover a 

 circular surface wliose diameter was s() niicra. It was xvvy active. 



maintained a film- or sheet-like structure which was about 5 or 10 

 micra thick. The protoplasm was highly vacuolated by non- 

 contractile vacuoles. The degree of vacuolation varied at dif- 

 ferent stages of vital activity. When most highly vacuolated the 

 vacuoles approached equality in size. The body was also marked 

 with numerous, more or less equal, "pearl-like" granules. The 

 rather short, unequal, pointed, and unbranched pseudopodia were 

 given off from the margin of the body. They contained no vacu- 

 oles nor refractive granules. When vacuoles and refractive gran- 

 ules were pushed out they formed processes which might bear one 

 or more pseudopodia. Most of these were given off from an ab- 

 solutely transparent marginal layer of protoplasm. Subsequently 



