118 Transactions. — Zoology. 



V. Planoveuter varicolor, sp. nov. Plate IX., figs, v., v. a., v.b. 



Specific characters : There is no need of these till more 

 species are placed in this new genus. The specific name 

 chosen is given because the various colours are both very ob- 

 trusive and unlikely to be found in any species that may be 

 afterwards discovered. 



This Rotifer is very prettily coloured. The ovary, which 

 is large and prominent, is of a deep salmon-colour, and the 

 general colour of the body is a light-salmon. The walls of the 

 stomach and intestines are remarkably thick, and are of a 

 bright-yellow colour. The eye is of a brilliant red, and the 

 brain also is tinged with a dark crimson-lake. The stomach 

 is usually filled with a medley of green and yellow and brown 

 food-matter, so that altogether the Rotifer is a very attractive 

 and beautiful object, only the two extremities being without 

 colour. In general shape it is fish-like, its greatest diameter 

 being just anterior to the middle of the body, and taper- 

 ing to both head and tail. The foot is very small, being 

 chiefly composed of two fair-sized toes. The head is not 

 distinctly marked o& from the body. The corona is prone, 

 hardly at all encroaching on the anterior pointed part of 

 the head. The mouth, too, is ventral in the centre of 

 the corona The gullet passes upwards and backwards. 

 The trophi are very close to the mouth, and they are 

 often extruded therefrom with a remarkably active snap- 

 ping movement, so that, as Hudson says, it is difficult to 

 believe that you do not hear them close on each other. They 

 are of the forcipate type of trophi, quite similar to those of the 

 SalpinidcB and Furcularians. The stomach is capacious, and 

 fills the middle third of the body. It narrows to the intestine, 

 which opens dorsally just in front of the foot. The walls of 

 both these parts are very thick, yellow in colour, and marked 

 all through with black dots. Possibly these thickened walls 

 may have some physiological significance. I noticed no par- 

 ticular muscles, except the pad surrounding the mastax. The 

 brain is large, depressed, and of oblong shape. It is situated 

 dorsally, just at the junction of what may be called head and 

 body. It is of dark-red colour. Immediately above it is a 

 pit in the integument reaching down to the brain, and leaving 

 onlv the thickness of the integument between it and the outer 

 air. I have never seen a pit of this kind in any other Rotifer, 

 nor have I ever seen it referred to by any writer on this sub- 

 ject. The eye is of a brilliant-red colour, and is probably 

 just the pigmented anterior face of the brain. This is very 

 frequently the case [cf. species III., V., IX. intra). The 

 two foot-glands are large, and very prominent. The ovary is 

 large, and of a deep salmon-colour ; it lies ventrally, and to 



