Fresh-water Entornostraca of South America. 



Remarks. — I have been in some doubt, as to whe- 

 ther the above-characterized form may not be the very same 

 as that recorded by Mr. Daday from Ceylon. This doubt 

 has not been removed even after I have had an opportunity 

 through the kindness of Mr. Daday, of examining his original 

 specimens. These are mounted in glycerine on a glass slide 

 in a shallow cell; but unfortunately, the specimens have been 

 somewhat crushed by the pressure of the cover, and their 

 exact form is accordingly impossible to make out. In any 

 case, the specific name «orientalis» would be very inappro- 

 priate to the Brazilian form. On the accompanying plate I 

 give exact figures of both sexes together with detail figures 

 exhibiting the structure of the legs and the caudal part, and 

 hope that thereby this interesting form may be easily 

 recognizable. 



Biological Observations. — This form was 

 observed at different times in 2 of my aquaria, and was 

 easily detected, owing to its comparatively large size and dark 

 brown colour. In habits it agrees with most other Lynceidæ 

 in so far that it is a true bottom-form, generally dwelling 

 in the loose mud, through which it forces itself with great 

 dexterity, chiefly by the aid of its very mobile caudal part. 

 At times, however, it is also to be seen movnig freely through 

 the water, or attaching itself to the walls of the aquarium. 

 The swimming motion of the animal is rather rapid, and 

 somewhat recalls that of Eurycercus lamellatus, consiting of 

 a vigorous leap through the water, during which the body 

 is kept in a horizontal attitude, with the back downwards 

 At the close of the seasons the greater number of the 

 specimens were seen to produce resting ova, only a single 

 such ovum of inconsiderable size and very dark colour being 

 found in each individual, located in the anterior part of the 



