,330 C. F. ROUSSELET ON BRACHIONUS BAKERI. 



and in my experience this antenna has always a nicely rounded 

 recess to lie in, and not a sharp angle as shown in Grosse's figure. 



The shell of B. bakeri is more or less stippled all over (usually 

 closer and more strongly marked than the figures indicate), 

 sometimes very prominently, and in regular lines and patterns, 

 and sometimes very faintly and hardly visible ; as a rule the 

 stippling is strongest in the long-spined varieties and weakest 

 in the short-spined animals, which may be called var. brevi- 

 spinus, the only additional name which I would admit. 



The lorica is compressed dorso-ventrally, more so than in 

 most other species of Brachionus, and as a consequence the 

 internal organs, and especially the gastric glands, are spread 

 out and lie natter. Otherwise there is hardly any distinctive 

 feature in its internal anatomy. 



All the figures in Plate XVI., except Fig. 11, have been 

 very carefully drawn by Mr. F. R. Dixon-Nuttall from mounted 

 specimens in my possession. Figs. 1, 2, and 3 represent a 

 dorsal, side, and ventral view respectively of the more common, 

 and what may be considered the type species. The animal 

 represented in Fig. 4 I obtained from a gathering sent me from 

 America, and collected in the Illinois River ; the spines are 

 all very long and the posterior spines diverging. In the same 

 gathering were also numbers of similar animals with shorter 

 and straighter spines. A similar long spined variety has been 

 reported from Lake Yamouneh, in Syria, by Mr. Barrois, 

 who has called it B. melhemi. The animals figured in Figs. 

 7 and 8 were obtained at the Commercial Docks, the 

 spines are short and stout, and some specimens had the 

 merest indication of posterior spines, as seen in Fig. 7. 

 The shells represented in Figs. 5 and 9 come from 

 the Victoria Regia tank in the Royal Botanic Gardens in 

 Regent's Park, where this variety can almost always be found ; 

 the lorica is very transparent with hardly any stippling. The 

 animal drawn in Fig. 12 w r as obtained at the Club's excursion 

 to Hanwell. When I first saw it I was for a moment in doubt 

 what to call it, as there is not a trace of posterior spines, the 

 lorica being perfectly round with a long sweeping curve, very 

 slightly indented in the middle.* I could find only this single 



* This appears to be the variety found by Mr. A. S. Scorikow, near 

 Kharkow, in Russia, and named by him B. cluni&rbicidaris. 



