30 G. 0. Sårs. 



cidæ. As seen from the figures 5 — 10, the structure of the 

 legs, which was not made out by Mr. Richard, is rather 

 peculiar, especially in the total absence of epipodites in the 

 3 anterior pairs (figs. 6, 7, 8), whereas in the last 2 pairs 

 (figs. 9, 10), these appendages are quite extraordinarily de- 

 veloped. The structure of the caudal part (fig. 4) also differs 

 considerably from that in any other known Macrothricid. 



Biological Observations. — At first only a few 

 female specimens of this peculiar form appeared in some of 

 my aquaria, and immediately attracted my attention by the 

 reddish brown colour of the animal and its peculiar manner 

 of swimming. In the course of the season these specimens 

 multiplied rather abundantly; but I was long unaware of 

 this augmentation of the specimens, owing to the peculiar 

 habits of this form. It was, indeed, a very rare event to 

 catch sight of some solitary specimens, when examining the 

 aquaria from without by the aid of a magnifying glass. How- 

 ever, on applying an ordinary dipping-tube, by the aid of 

 which small quantities of the bottom material were taken up, 

 I succeeded in almost every case in getting some specimens 

 of this form, which accordingly in reality proved to be pre- 

 sent in the aquaria in great abundance. It is, indeed, as 

 suggested by Dr. Richard, a very pronounced bottom-form, 

 keeping almost constantly on the ground, like most of the 

 Lynceidæ, and only quite occasionally making a short excurs- 

 ion up from the bottom. Its movements are rather slow, 

 and effected in a pronouncedly jumping manner, during which 

 the body is kept in a prone attitude. I have never seen it 

 attaching itself to the walls of the aquarium or to the aqua- 

 tic plants growing in it, though it may be able for some 

 short time to cling by the aid of the anterior pairs of legs 

 to mud particles or other objects lying on the bottom. 



