BRACHIONIDJE. 119 



where the species is named rubens.) The eye consists of three cells of ruby crimson, 

 from the edges of each of which, under sunlight, brilliant reflection is seen. P.H.G.]. 

 Length. Of lorica, ' 5 inch ; total, foot and head extruded, ^ inch. Width T } 5 inch. 

 Habitat. Ponds and ornamental waters near London ; Birmingham (P.H.G.) : rather 

 uncommon, 



B. RUBENS, Ehrenberg. 

 (PL XXVIL, fig. 5 ; and PI. A.) 

 Brachionus rubens . . . Ehrenberg, Die In/us. 1838, p. 513, Taf. Ixiii. fig. 4. 



[SP. CH. Nearly as the preceding, but the occipital spines have the form of saw- 

 teeth, sloping inward ; and of the pectoral edge the central elevation is more marked. 



I have strong doubts whether B, urceolaris and B. rubens are specifically distinct. 

 Very different individuals may, indeed, readily be presented ; but a series do certainly 

 run into each other. Considering them for the present as distinct, I refer to the figs. 

 on Plate A, and its explanation, in which it has been selected for illustration as typically 

 representing the organization of the whole class. In examples which we may call more 

 characteristically rubens, we may see the gastric glands in a very peculiar condition ; 

 each consisting of two sacs, quite distinct, each separated by a long duct, and the inner 

 one leading by a duct to the oesophagus, while the outer is manifestly united with the 

 lateral canal. Then the canals themselves form several distended sacs with necks, 

 just before they enter the contractile vesicle, which is here unusually small, for the 

 genus. P.H.G.] 



Length and Habitat. As the preceding. 



B. MULLEBI, Ehrenberg. 

 (PI. XXVIL fig. 7 ; and PL XXX. fig. 8.) 



Brachiomis Millleri . . . Ehrenberg, Die Infus. 1838, p. 513, Taf. Ixiii. fig. 5. 

 hepatotomus . . Gosse, Ann. Nat. Hist. 2 Ser. vol. viii. 1851, p. 203. 



[SP. CH. The occipital spines reduced to low saw-teeth, much wider than high, 

 with their outer edges sinuate ; the pectoral line nearly straight, notched into round 

 lobes. Marine. 



This is a very fine, elegant, and attractive species ; and its marine habitat at once 

 distinguishes it. I obtained it on the Essex coast six-and- thirty years ago ; and 

 recently Mr. Hood has sent it to me in abundance from tide-pools in the Firth of Tay, 

 and Mr. Brightwell from Norfolk. It is a good traveller and lives long in small phials. 

 I have had it in abundance in my own marine aquarium. 



Each gastric gland is a great sac divided nearly to its base, so as to appear two ; and 

 these vary greatly in shape and in relative size. They are very distinctly connected 

 with the lateral canals. Both male and female eggs are carried, and males are pro- 

 duced in abundance. The middle of the body in this sex is occupied by the spermatic 

 sac, a great pyriform vessel connected by a bottle-like neck with the head-mass. On 

 pressure this sac is seen to be full of bodies having a vermicular motion ; and, on the 

 pressure being continued, it bursts, freeing about thirty spermatozoa of unusual size, each 

 being ,5^ inch long, a slender body merging into a long whip-like tail which maintains 

 a quivering undulatory motion for several minutes after exclusion. P.H.G.] 



Some fine specimens sent to me by Mr. J. Hood enabled me to make a drawing of 

 the ventral aspect of this Brachionus (PL XXX. fig. 8), and to add a few notes to the 

 above. The transparent vesicles which embrace the buccal funnel, and, resting on the 

 mastax, reach up to the head, are here unusually large and conspicuous. Th lateral 

 antennae can be readily seen protruding the tips of their heads from a dent in the lorica 

 on either side just below the gastric glands : they are here, as is often the case, attached 

 also to the floccose investment of the lateral canals, and their nerve -threads are obvious. 



