864 Transactions of the Soeietif. 



general embryonic vesicles more or less conspicuous. The long foot and 

 toes are carried straight behind, and both extended are about as long as 

 the trunk. It is, as usual, restless, moderately swift, with a smooth 

 gliding course. It is an elegant and attractive little species, which, for 

 lack of any very marked characteristics, I name from the locality in which 

 I found it, — the Kingskerswell mill-stream. Here, on different 

 occasions, I have met with several examples. (Fig. 6.) 



7. Furcularia sph^erica. Body globose dorsally, nearly flat 

 ventrally : foot short, thick ; toes small, straight, acute ; the dorsum 

 projecting over them with a slight rim or margin, which, laterally seen, 

 looks like a tail. Length 1/240 in. Marine and lacustrine. 



In lateral aspect this pleasing little form may easily be mistaken for 

 a deep Colurus, till the trophi reveal its true Furcularian character, 

 confirmed by a minute ruby eye at the extreme front ; as also by its 

 motions. The head seems not retractile. I first formed acquaintance 

 with it, in half a dozen examples on different occasions, from tide-pools 

 in the Firth of Tay. Then a specimen, recently dead, occurred in fresh 

 water among Myrio;phyUum, thickly studded with Melicerta ringens and 

 Floscularia cornuta. And presently, to confirm the amphibious habitat, 

 I found one alive in Utricularia from a lough in the centre of Ireland. 

 These fresh-water specimens I could in no wise distinguish from the 

 marine. (Fig. 7.) 



8. Furcularia sterea. Body ovato-cylindric, with a thick truncate 

 head, and subprone face ; behind ending in a short, decurved, acute tail : 

 foot short and thick, apparently one-jointed ; toes moderate, acute, 

 scarcely decurved. Length 1/173 in. Lacustrine. 



Having much in common with F. molaris, this is yet quite diverse 

 in facies and habit. The head is of nearly the same thickness as the 

 trunk ; the little overarching tail (seemingly a stiff point), and the short 

 but massive foot, are differences that strike one at first sight. The eye 

 is distinct, quite prominently frontal ; immediately beneath it the face 

 recedes, and becomes a subprone ciliate surface, applied to the feeding- 

 ground. It is much larger than F. molaris. The single specimen seen 

 had a great contractile vesicle, and a small undeveloped ovary. The 

 stomach seemed undivided. The fore-parts were tinged of a delicate 

 yellow hue. It was not much addicted to swimming, but crept viva- 

 ciously about the vegetation, grubbing and browsing. I obtained it in 

 water from a little rockery-pond in the grounds of Watcombe Park, the 

 beautiful estate of Colonel Wright, near Torquay. (Fig. 8.) 



9. Furcularia Eva. Body stout, fusiform, strongly elevated on the 

 shoulder : foot short, indistinct ; toes more than half as long as body- 

 and-head, thick for half this length, then abruptly attenuated for the 

 remainder. Length 1/144 in. Lacustrine. 



The great length and peculiar form of the toes, which are often 

 thrown back and carried over the back, give a facies to this rather fine 

 species, which at once strikes an observer. Sometimes these organs are 

 extended in opposite directions in a horizontal line, imparting to the 

 animal the figure of the letter T reversed. The mastax is ample ; the 

 incus a thick rod, bent in the middle backwards, and ending occipitally 

 in a pair of long and broad scythe-shaped processes : the mallei indistinct. 



