58 THE ROTIFEEA. 



GOMPHOGASTEB AEEOLATUS, VoTCC (210), (PL XXXIV. fig. 36). 

 Plcesoma lenticulare Herrick (175). 



A single specimen was found by Mr. Vorce in 1882 ; it was taken living in filterings 

 from the water of Lake Erie, at Cleveland, Ohio. Lorica thick and strong, dark coloured, 

 marked all over with areolar depressions, very much resembling the markings of 

 Hemiaulus ; sides slightly concave, a deep plicate furrow across the back at the widest 

 part, from which two deep sub-central furrows, and two shallow sub-marginal furrows, 

 extend upon the dorsal surface to the posterior tip of the lorica ; lateral margins of the 

 dorsal front of lorica slightly produced, making the corners prominent. Foot stout, two- 

 jointed ; toe apparently single ; retractile horns very slightly clavate. Eye-spot not 

 observed, but if present would be usually concealed by the dark lorica. Cilia of the 

 corona robust, in a single (?) marginal row. Animal very active and strong, pushing 

 its way among masses of diatoms and flocculent matter, and when entangled freeing 

 itself by vigorous kicks with its strong foot. 1 Mr. Herrick (who found this animal 

 several times in a reservoir near Hebron, Ohio) says that there is a ventral prominence 

 on the head, bearing several long setae ; that the trophi are feeble ; the eye cervical, 

 and seated on a considerable ganglion ; and that the foot has two appressed toes. 



Length, cir. T ^ inch. 



DOUBTFUL AND EEJECTED GENERA. 

 Genus AETHHOCANTHUS, Schmarda (184). 



A genus formed to contain the varieties of Brachionus pala with long posterior 

 processes on the lorica (vol. ii. p. 117 ; PI. XXVIII. fig. 3). 



Genus ASCOMORPHA, Perty (124). 

 The same as Mr. Gosse's genus Sacculus. 



Genus BORTHRIOCERCA, Eichu'ald (167). 



The only species, affinis, is evidently some Rotiferon belonging to the Rattulida, but 

 the figure and description are too vague for its identification. 



Genus CYCLOGLENA, Ehrenberg (42). 



A genus formed by Ehrenberg to take Notommatce with more eyes than three, in 

 a cluster, in the neck. There are two species, lupus (PL XXXIII. 15) and elegans. The 

 former has a cluster of red specks in the neck. It is like N. aurita, but has no auricles, 

 and is said to vary in length from T ^ T to \ inch which seems incredible. 



The latter, Ehrenberg himself marked as a doubtful species. It is -5^ inch in length, 

 and the drawing (from which little can be learnt) shows a row of spots stretching from 

 above the stomach for a quarter of the animal's length : these could scarcely be eyes. 

 It was found in Nile water : lupus, at Berlin. 



Genus CYSTOPHTHALMUS, Corda (23). 



In this genus there is but one very doubtful Rotiferon, C. Ehrenbergii (PL XXXII. 

 fig. 22). This creature reminds one of a Taphrocampa. It is grub -shaped, tapering at 

 both ends, and divided into fourteen or fifteen segments by muscular rings. The last 

 two segments are of very much smaller radius than the preceding one, and form a sort 

 of tail. There are a few cilia, surrounding a buccal orifice, on the ventral surface. 

 This opens into a short buccal funnel leading to a pear-shaped sac (fig. 6), round the 

 inner walls of which are arranged four pairs of jaws, like curved rami on a dumb-bell- 

 shaped fulcrum. A shorter, ringed oesophagus connects this sac with a simple conical 



1 The whole of the above description, of this very curious Rotiferon, has been taken from Mr. C. M. 

 Vorce's interesting paper (210), read before the American Society of Microscopists in 1887. 



