150 C. F. ROUSSELET ON BRACHIONUS SERICUS 



shown in Fig. 6. I have therefore named this B. quadratics 

 var. rotundas. A second difference to be noted is that the median 

 of the three spines guarding the foot opening is reduced to a 

 rounded projection. 



The drawing (Fig. 6) shows a series of fine longitudinal and 

 transverse curved surface markings of the lorica ; with the 

 exception of the two median ridges these are really very faint, 

 mere creases in the chitinous integument, and easily over- 

 looked; they are, however, permanent and present also in the 

 type species. The lace-like structure of the lorica is not shown, 

 because it requires much greater magnification to render it 

 visible. 



The foot is long, stout at the base and tapering somewhat to 

 the toes ; it is transversely wrinkled and also shows the faint 

 pseudo-jointed appearance characteristic of the type species. 

 The small male eggs and larger female eggs are smooth and 

 normal ; the fertilised resting egg, however, is very peculiar, oval 

 in shape, and covered all over with closely set stout cylindrical 

 papillae as represented in Fig. 8. I had not seen the resting egg 

 of B. quadratics when describing this species in 1889, but have 

 found it since, and it is identical with the above, which is another 

 link connecting the two animals. 



The male (Fig. 7) was hatched from male eggs and corresponds 

 in shape and structure to most other males of this genus, the 

 chitinous integument being very thin and flexible. 



The internal anatomy of B. quadratics var. roticndics is quite 

 normal, and requires no further description. The size of lorica 

 is 272 ix (^in.), of resting egg 136 /* (y^in.), of female egg 

 122 fx (o-foin.), of male egg 75 /x (^ in.). 



Amongst the other known species there is one, namely, 

 Brachionus leydiyii of Cohn, which bears considerable resemblance 

 to B. quadratics and the var. roticndics, and there can be no 

 doubt that the three are closely allied and belong to the same 

 group. 



