352 



II. H. Anderson — Notes on Tiulian Botifers. 



[No. 4, 



bodj' cfivity of fheir parents. In many cases, the young ones were longer 

 than the length of their progenitor, and the long foot might be seen 

 moving about, now drawn back into the body, and now extended to a 

 considerable length around the viscera. The mastax and, in more than 

 one instance, the cilia wore in constant motion. 



The frontal column when extended fully is tipped with cilia which 

 vibrate actively. It was only on rare occasions, though, that I was able 

 to see them, as they seemed to be rarely extended. 



The habit of this Actinunis differs under different circumstances. 

 As usually seen it is in constant motion, creeping actively or swimming 

 over the field of view. But on one occasion I had enclosed a small 

 Lemma leaf and the AcHuuri, under the cover glass, took their places 

 under this, fastening themselves well underneath, bat so that their 

 bodies projected when they wore fully extended. On this occasion I 

 was enabled to get a very satisfactory view of the organs and internal 

 arrangement, though, owing to the thickness of the leaf, I could not use 

 a high power. 



There is one point on which I speak with some hesitation. I 

 noticed in one specimen that there was only one tooth on one ramus 

 and two on the other. I examined this specimen very carefully and 

 several others also with a high power (750 diameters), and in several of 

 the latter observed the same. In others I thought I could see the two 

 teeth on both rami. In PMlodina erythropMhalma an unequal number 

 of teeth has been observed by Hudson, but in no species, as far as I 

 know, has only one tooth been seen. But in several instances the one 

 tooth, with the minute ridging parallel to it, was so very clear that 

 I do not think I can have been mistaken. 



The size of an average specimen when fully extended is to 

 of which the body is about jV" ^^'^ aV") breadth of the 



body at its widest ^io"- Contracted the same specimen would be about 



long by XT?" "wide, but there is considerable variation in size. 



Order III. PLOIMA. 

 Sub-order ILLORICATA. 



Family X. Notommatadae. 



17. NOTOMMATA ANSATA, Ehrenbcrg. 

 First seen, December 14th, 1888. Not uncommon. 



18. NoTOMMATA Tuipus, Ehrcuberg. 



Common. 



