48 THE ROTIFERA. 



hanging lip, to be presently withdrawn. The principal shield protects the back of the 

 head, but does not form an arching hood, or frontal hook. The trophi, in several good 

 views, seemed of the pattern (fig. 39 of my Mem. " On Mandiic. Org.," Phil. Trans. 

 1850) assigned to Notomm. gihba. The whole facies recalls one of the smaller Notom- 

 viata ; yet the two well-defined eyes remove it from them ; besides the manifest lorica. 

 It seems to approach the marine genus Mytilia, but not very close. 



Only a single specimen occurred, in June. It was active and busy, constantly 

 turning and wheehng about, but little given to locomotion. It suggests the odd notion 

 of a creature carrying its great clumsy head in a bandbox. 



Length, ^^^j inch. Habitat. Lacustrine. P.H.G.] 



MoNUEA BAETONiA, Gosse (171), (PI. XXXI. fig. 49). 



[SP. CH. Lorica ovate, vwdcrataly comjiressed, dorsal outline {vieioed laterally) 

 one-third of a circle, ending in triawjular points, which have the dorsal side slightly 

 excavate; one eye frontal ; toe straight, slander, acute, more than half as long as the 

 lorica, shmddered dorsally. 



The genera Colurus and Monura (if, uideed, they are not one) appear to contain'' a 

 large number of species, peculiarly difficult to define satisfactorily. Yet this and the 

 foUowmg are, I think, to be distinguished. The toe and foot together are nearly equal 

 in length to the lorica. I could find no trace of a median line in the toe. Its extreme 

 length and tenuity are notable. Each posterior point of the lorica forms an equilateral 

 triangle, clearly defined from the general area of the lorica, by a line — the base of the 

 triangle. These two triangular termini are of excessive delicacy, and may easily escape 

 a cursory notice. On the extreme front, under the frontal hook, is a small dark crimson 

 eye, like a wart on the face. 



Its manners are those of so many of its fellows, remaining long totally withdrawn 

 between the closed lorica-plates in front, pivoting and swaying on the toe-tip incessantly 

 for hours. I first obtained it, in the spring of this year, from a pond known as the 

 Reservoir, at Barton, near Torquay. Since then I have met with single specimens from 

 many localities, and in abundance in the Kingskerswell mill-stream. 



Length (from hook to toe-tip), ylj inch. Habitat. Barton ; Kingskerwell. P.H.G.] 



MoNUEA LONCHEEES, Gossc (171), (PI. XXXI. fig. 50). 



[SP. CH. Dorsal outline narrowly ovate, lateral nearly semicircular ; lorica 

 rounded behind, with a median angular notch ; toe shouldered dorsally, excessively 

 long and slender. 



The most striking points in this beautiful species are its great depth (from back to 

 belly), making about a half-circle, and the tenuity of the toe, which seems indivisible. 

 This runs to so exceedingly fine a point as to escape notice, except with the most 

 delicate focusing ; even with a quarter objective, and the best possible light. The 

 foot, of two condyliform joints, and the toe, together, are fully equal to the lorica in 

 length ; viz. -f^ inch. The ventral cleft is narrow, straight-sided, slightly approximate 

 in front, and reaching round to the occiput, posteriorly to a short acute sinus whose 

 sides form a right angle. There is a brilliant ruby eye about the middle of a saccate 

 bram, and therefore cervical. 



I have examined a number of examples, at different times, in sea- water obtained by 

 Mr. Hood from the Invergowrie tide-pools. In one of these I timed the period of 

 emptying the contractile vesicle to be just three minutes. It had this peculiarity, that 

 the emptying was but partial on each occasion ; that the bladder suddenly diminished 

 its volume, but not to a point, nor nearly. The animal's posturing manners are exactly 

 the same as described in the preceding species. 



Length (total), o J ij iw'^li' Habitat. Invergowrie tide-pools. P.H.G.] 



