FROM THE ENGLISH LAKE DISTRICT. 363 



Remarks on some of the Species. 



Amoeba VBSPERTILIO, Penard, ' Faune rhizopodique du Bassin die Leman,^ 

 1902, p. 92. (Plate 50. figs. 1 & 2.) 



Though it is doubtful whether all the various forms o£ Amoehce described 

 by different authors are reallj distinct species, it seems to me that A. vesper- 

 tilio is quite characteristic. I have found it, not only in Esthwaite Lake 

 but also in sediment from near Sheffield, and always having the same features. 

 It is somewhat variable in form, but during movement always possesses a 

 broad clear belt of ectoplasm in front, from which arise the characteristic 

 sharp-pointed cone-shaped pseudopodia. The endoplasm is fairly granular 

 and contains various inclusions, mostly food-bodies (Algie). There are 

 generally several vacuoles which tend to flow together, forming a laroe one. 

 The nucleus is single, slightly oval, with a central mass of chromatin matter 

 (" nucleolus ") surrounded by a clear border. Size about 50 yct. 



UlFFLUGiA RUBESCENS, Pencird, ' Rochi/ Mountain Rhizopods,' in ^American 

 Naturalist,^ 1891 ; ''Faune rhizopodique c^c.,' p. 227. (Plate 50. figs, 3, 4, 5.) 



This species does not seem to have been recorded for this country before. 

 The test is pyriform in outline, but shorter in proportion than that of 

 D. oblonga {= piriformis) . It is transparent, consisting of thin flakes and 

 broken diatom frustules. The neck is almost uniform in width and quite 

 distinct. Within the margin of the mouth a series of blunt tubercles or 

 tooth-like projections is to be noted (see fig. 4), This character is not men- 

 tioned by Dr. Penard, but all my specimens, whether collected in the Lake 

 District or near Sheffield, showed it. The protoplasm does not nearly fill the 

 test and is attached to the fundus by several clear epipodes. When the 

 animal is active the protoplasm projects from the test as a distinct column 

 from which one, or occasionally two, finger-like pseudopodia arise. 



A characteristic feature is the presence of numerous round, brick-red 

 granules in the endoplasm, especially in the region towards the mouth. They 

 are always present, and when the animal is extended they project to the 

 origin of the pseudopodia, or even into them for a short distance. The 

 nucleus is single and distinctly seen. Size 80 yu. in length by 55 /j, in breadth. 



DiFFLUGiA lanceolata, Penard, in ' Mem. Soc. phys. et hist. nat. Geneve ' 

 1890 ; ' Faune rhizopodique 4*c.,' p. 250. 



Associated with 1). oUonga one often meets with individuals belonoino- to 

 this species. The character and shape of the test readily distinguish it, being 

 lanceolate and not pyriform, with generally a rounded, but occasionally a 

 bluntly-pointed, fundus. There is no indication of a neck. The test is 

 covered with thin flakes and rarely carries large grains, so that the outline 

 is uniform. Size 146-160 /* in length. 



