130 Transactions. — Zoology. 



To avoid making too many species I have put this under 

 the same name as the Eotifer ah-eady described by Ehrenberg. 

 One of the chief differences between this New Zealand variety 

 and that of England is its much greater size, being probably 

 twice the size of the already described acuminata. The other 

 varietal differences noted are — (1) My variety has no dorsal 

 cephalic lorical cleft ; and (2) the trophi here are well forward 

 in the head, and not back in the neck. Sinking these three 

 differences, the two agree perfectly. Colour, absolutely none. 

 It is greatly depressed, and of a graceful outline. Eather 

 narrowed in front, it swells out till it reaches its gjreatest 

 breadth half-way back. Then, narrowing rather rapidly, it 

 ends in the sharp median spine of the lorica. The foot is 

 rather short, and composed of three telescopic joints, and 

 ends in two small narrow toes. It trails behind the body 

 when the animal is in motion. The head protrudes, extending 

 forward the regular shape of the body. The cilia fringe the 

 anterior border of the head, and are rather small and nu- 

 merous. The lorica partakes of the graceful shape of the 

 body. There are two blunt lateral spines in front, and the 

 sharp median one behind. It is, of course, arched dorsally ; 

 flat and incomplete behind ventrally. An arched retractile 

 chitinous plate covers the head. The mouth is on the centre 

 of the anterior ventral edge of the head. The trophi, which 

 are situated well forward in the head, and are of rather small 

 size, belong to the malleate type. The muscles working the 

 trophi are strong, especially the band joining the opposite 

 manubria. The lateral muscles of the foot are strongly de- 

 veloped. There is no brain nor sense-organ of any kind, as 

 far as I could see. A small bright spot occurs on the left 

 edge, near the dorsal side, and about one-third the way back 

 from the head; this is probably one of the "oil globules" 

 found in Colurus. 



The movements of this Eotifer are rather peculiar. It 

 floats slowly forward to a piece of Alga, then flecks its foot 

 sharply sideways, and so springs backwards. Its foot slowly 

 swings back to its first position, while the Eotifer is again 

 progressing by means of its cilia. It always swims on its 

 ventral surface, owing to its depressed shape. I saw only two 

 specimens of this species, close together on the same slide. 

 They came from the same prolific pool. 



XV. Metopidia solidus, Gosse. Plate XL, figs, xv., xv.a., xy.b., 



XV. C, XV. ^. 



Specific characters : Lorica nearly circular, depressed. 

 Ventral plate commensurate with the dorsal, but more deeply 

 excavate in the posterior notch. The dorsal plate has a sub- 

 marginal line of corrugation. 



