ROTATORIA 171 



f. brchmi Klausener. Both posterior spines absent, reticulate sculpture present (Brehm 

 and Zederbauer, 1904, fig. 1 ), punctate apparently absent. 



f. aspina Fadeev. Both posterior spines absent, reticulate sculpture almost and punctate 

 entirely absent. 



If Fadeev is correct, in South Russia aspina is to be regarded as the extreme reduced 

 phase of tropica, i.e. tropica-hreluni, and rediicta an intermediate between tropica-mofisfrosa 

 and this extreme reduced phase. More knowledge is clearly needed of the cyclomorphosis of 

 tropica forms before it is certain that the extreme reduction in sculpture noticed in aspina is 

 really characteristic of this series of forms. In the only South African locality that has been 

 followed throughout an entire year, Florida Lake, near Johannesburg (Schuurman, 1932), 

 the species appears stable, but a spineless unsculptured form which we would refer to aspiiia is 

 recorded from certain shallow pans, as has been already indicated. In the present collec- 

 tions a single specimen which may be referrd to tropica (Figure 4) occurred in the plankton of 

 the lake at Ootacamund, in which K. quadrata f . diz'crgens was abundant. A few very similar 

 specimens occurred in the pond at Sohawa designated as P 2, where a single short subequal 

 spined form with a pentagonal posterior polygon (Figure 4) here referred to f. z'alga was 

 also obtained. Both the Sohawa and Ootacamund K. valga f. tropica have well-developed 

 punctate as well as reticulate sculpture. In Wular Lake a very long spined form which may 

 be referred to tropica-nwnstrosa (Figure 4) was not uncommon and in the same locality a 

 very few specimens of f. tropica-asymmctrica were also obtained (Figure 4). The punctate 

 sculpture in these Kashmir specimens is considerably reduced. 



It is clear from Jakubski's (1916) record and from some of Klausener's data that the 

 asymmetric condition does not always involve reduction of the left, but sometimes also of 

 the right spine. It is highly probable that truly dextral and sinistral forms may occur, with 

 a concomitant difference in the sense of their spiral swimming movements. Such a possi- 

 bility is of great biological interest and would merit close attention on the part of any worker 

 to whom living material is available. 



Certain names applied to forms of K. quadrata and K. valga or included under the 

 former species by Harring remain to be considered. 



Anuraca scutata Thorpe (1891) from Brisbane appears to be allied to K. valga f. asym- 

 mctrica but such sculpture as is indicated seems to show the median cariniform arrange- 

 ment of the mid-dorsal reticular partitions characteristic of K. cochlcaris (Gosse). The 

 dorsal surface is said to be markedly gibbous in lateral view. In view of the doubt raised 

 by the sculpturing the name scutata Thorpe is iiest suppressed unless an animal identical with 

 the figure remains to be rediscovered. 



Anuraea procurva Thorpe (1891) from the Island of Ascension is in form nearer to 

 quadrata than zvlga but is distinctly asymmetric in its posterior spines. In side view the 

 lorica is seen to be bent forward, particularly in its ventral part, in a most peculiar manner. 

 This form is probably best retained as a somewhat doubtful species under the name of 

 Keratella procurva (Thorpe). 



Anuraca stipitata var. Warlnianni Asper and Heuscher (1889) is another problematic- 

 form but there seems no reason to treat it as a synonym of K. quadrata f. curvicornis, as 

 is done by Weber (1898). 



