Hood — On the Rotifera of the County Maijo. 693 



short distance from the mouth of a stream running into Clew 

 Bay, Louishurgh, 1889. 



A. testudo, Ehrenb. H. and G., Supplement, p. 55, pi. xxxiv., 31. I 

 found a few examples of this species in Castlebar Lake, 1891. 

 Its markings are not unlike those of A. serrulata, Gosse, but 

 it differs from the latter in having two posterior spines, and in 

 the two median frontal spines being straight. 



A. schista, Gosse. H. and G., Supplement, p. 56, pi. xxxi., 55. 

 Numerous in a pond near Westport, 1894, associated with 

 Brachmius rubens. 



Notliolca longispina, Kellicott. A few examples of this beautiful and 

 remarkable species occurred in Castlebar Lake, 1891. This is 

 the only Rotifer that can swim backwards quite as well as for- 

 wards. I found it again in a clear lake near Westport in 1894, 

 associated with ConocMlus unicornis. 



N. acuminata^ Ehrenb. Eairly numerous in a marsh near Westport, 

 1892. 



N. scapha, Gosse. This species is quite at home either in fresh or 

 salt water. I found many examples in a mossy pool on the side 

 of a hill in the Croagh-Patrick range, 400 feet above sea level, 

 and again in a tide-pool by Westport Harbour, 1891. 



N. spinifera, Hood. Science Gossip, ISTov., 1887, p. 248, figs. 134, 

 135. Gosse, in H. and G., Supplement, p. 57, pi. xxxi. 6. 

 (Plate XXII., fig. 8, 8 b.) 



As there is a slight error in regard to the lateral spines of 

 this species both in my own original description and in that of 

 my departed friend Mr. Gosse, and as several other points in 

 its structure have been better observed since these former 

 observations were published, I here give an amended de- 

 scription of the animal. Specific Characters. — Lorica broadly 

 sub-rhomboidal ; the dorsal plate slightly less than the ventral, 

 and joined to it by a thin elastic membrane. On the dorsal 

 plate in the lumbar region are a pair of hinged spines, one on 

 each side, which can be extended and folded up at the will of 

 the animal. When folded, the spines fit into an indented recess 

 on each side of the dorsal plate. The dorsal plate is striated, 

 and is furnished in front with six spines like the teeth of a saw. 

 The median pair and the outer ones are nearly equal in length, 

 the intermediate pair being somewhat shorter. The animal is 



