Some African Rotifers. By J. Murray. 7 



is long. No teeth, in the ordinary sense, can l>e distinguished, but 

 the whole jaw is crossed by excessively fine stria?, such as are 

 found on the jaws of all Bdelloids, in addition to the thicker teeth. 

 A ciliated tube could be distinguished in the lower part of the 

 stomach. The foot is 3-jointed. Toes not seen. 



Incomplete though the study is, this is obviously an animal of 

 importance. The characters of the corona and jaws would indicate 

 a pellet-maker, but the narrow alimentary tube shows that it is 

 not. According as the fine stria? on the jaws are regarded as teeth 

 or not, the animal may be supposed to approximate to Ehrenberg's 

 Callidina elegans (8) or to his C. edentata (11), a suggestion made 

 on the strength of the name alone, as I have not been able to 

 find the diagnosis. Mr. Bryce (-7) has shown that C. elegans pos- 

 sesses, according to Ehrenberg, a long foot and long spurs. 



In the genus Callidina, to which this animal seems to belong, 

 there are no species having numerous fine teeth (when w 7 e except 

 C. elegans). Among the pellet-makers the distinction between the 

 stria? and teeth is frequently not at all clear. 



Callidina papillosa Thomp. (##). 

 Synonym: Macrotrachila papulosa. 



The species of the group which include Callidina papillosa 

 and C multispinosa are so extremely variable that they are very 

 puzzling to students. As there appear to be peculiar forms in 

 almost every land, it is always desirable to add as many details as 

 can be observed, not merely recording the occurrence of the species. 



The Central African form is of moderate size, fairly typical in 

 the arrangement of the warts. The teeth are only two in each jaw. 

 The mouth has a rosette of ridges surrounding it, as in Rotifer 

 longirosiris. The form is almost identical with one found by Mr. 

 Milne in South Africa. 



Callidina aculeata Milne (13). 

 Synonym: Macrotrachrta aculeata. 



Like all of the group of species to which it belongs (the multi- 

 spinosa. group) C. aculeata is extremely variable. The Central- 

 African form is very spiny. There are five transverse rows of 

 spines on the dorsal side of the trunk, two on the anterior trunk, 

 one at the broadest part of the central trunk, and two others behind 

 it, the last doubtfully on the 4th central or preanal segments. There 

 are many small spines on the rump and more on the foot. The 

 first foot- joint has a distinct annular swelling. The dental formula 

 is 2/2. 



A very similar form occurs in Canada. 



