GO THE ROTIFEEA, 



Genus NOTOGONIA, Pertij (121). 



The only species, N. Ehrenbergii (PI. XXXIII. fig. 88j, has a lorica wideiihig back- 

 wards from the front, and with its hind edge bounded by three concave curves. A three- 

 jointed foot bears two bristlc-hke toes. Perty draws an oval mastax and says that the 

 jaws are " rounded and strong"; and the teeth, "two or three." The two eyes are 

 wide apart in front, " very small and faintly red." He describes also, and figures, a 

 pair of curved organs which protruded frequently from the front of tlie head. 



Length, -r|^ inch. Habitat. Near Belp (Perty). 



Genua OTOGLEXA, Ehrenhcnj (42). 



Ehrenberg defined his genus Otoglena as containing animals, of his family Ilydatinaa, 

 with one sessile cervical eye, two stalked frontal eyes, and the foot forked. The genus 

 included only one species, viz. 0. painllosa, and I have little doubt from his description 

 that it was a male Rotiferon, possibly that of A. viyrmdeo, to the female of which 

 Rotiferon he himself says it had much resemblance. The body was bell-shaped, swollen, 

 and rough with papillse ; the trophi were apparently absent ; the vascular system was 

 obvious ; the red cervical eye was attached to an oval nervous ganglion with two 

 dark appendages ; there was a long loop in the neck, and what Ehrenberg calls a 

 "respiratory opening" in the middle of the back, but which no doubt was one of the 

 usual setiferous pits in which the antenniB often end. Ehrenberg says that there was a 

 somewhat clotted stomach, and a very thin intestine ; but probably these were the 

 spsrm-sac and penis. The foot was conical, small, with very small toes. Ehrenberg 

 never met witli it but once. 



Length, ^^ inch. Habitat. Berlin (Ehr.) 



Genus PLAGIONATHA, Dujardin (40). 



In this genus Dujardin places together Notommata lacinulata, Distemma setigcrtini, 

 Batlulns tigris, Diglena caldlina, Notojjs hyptopus, &c. : on account of a supposed 

 similarity in their trophi. 



Genus TETBASII'HON, Ehrenberg. 



In Pritchard's Infusoria (4th edition, 18G1) the following description is given of 

 T. hydrocora, the only species of the genus. " Very large, hyaline, with two prominent 

 tubular occipital organs, and other two near the termination of the back ; gastric glands 

 four, globose ; jaws bidentate, with the oblique rotary organ of PleurotrocJui. Foot with 

 slender, long, and acute toes ; eye occipital. Length, ^j, inch, and upwards. Berhn." 



It is possible that this may have been Copeus spicatus ; for although the latter 

 has only iwo gastric glands, yet each of these is so deeply divided into two lobes, that 

 there often seem to be four. On the other hand, the trophi of C. spicatus are not 

 bidentate ; moreover no mention is made of the gelatinous covering, in which spicaius 

 is so often enveloped. 



Genus THEOKUS, Ehrenberg (42). 



A genus founded on the presence of two groups of supposed eyes, in the neck of a 

 Notommatoid Rotiferon. Ehrenberg describes these so-called eye-points as colourless 

 vesicles, but it is most improbable that they should be eyes at all. There were as many 

 as six vesicles in each group. Mr. Milne (186) has seen a similar group of vesicles in 

 each of the gastric glands of his Stephanops uncinatus. 



Genus TYPHLINA, Ehrenberg (42). 



The only species, T. viridis, was found by Ehrenberg at Cairo. He describes it as a 

 very small animal, 7^7, inch, without eyes, proboscis, or spurs, but with a sessile corona. 



