448 D. BRYCE ON MACIIOTRACHELOUS OALLlDINiE. 



define. The corona, very rarely displayed, is exactly equal in 

 width to the neck. When the wheels are at work the rostrum 

 remains extended. There are eight dorsal, but only four ventral 

 skin-folds. The spurs of the very short foot are usually spread out 

 in swallowtail fashion, and are not perforate, nor are they quite 

 constant in shape in different individuals. Each of the three short 

 toes has three perforations for the emission of mucus. Both the 

 yolk-mass and the germ-mass have eight nuclei. The outer 

 margins of the rami are thickened and dark yellow, and have a 

 comb-like edge. The supposed resting egg is described and figured 

 as having a few simple low prominences. 



The species is said to be a true moss form, which was only rarely 

 found in open water; its movements are extremely lively and 

 quick. It is with just a little doubt that I assign to it a form of 

 rather frequent occurrence in " dry " moss. The doubt arises 

 partly from my inability to make out so clearly as I could wish the 

 described structure of the rostrum, and partly from the form of the 

 eggs laid by isolated examples. These eggs were covered with 

 blunt spines, and were not resting eggs, but hatched out without 

 any long delay, the embryo moving within 12 days of isolation of 

 parents. In other respects the description fitted fairly well, both 

 as to structure and habits. I thought the upper lip, not mentioned 

 by Janson, was rather distinctive. It is simple in outline, and rises 

 nearly to level of discs, completely hiding the moderate gap be- 

 tween pedicels. The collar width was slightly less than that of 

 the corona. 



Callidina fusca, n. sp. (PI. XXIII., Fig. 2.) 



Sp. Ch. — Rather small, but stout. Skin of trunk greyish 

 or reddish- brown, rough and viscil, with coarse, irregular dorsal 

 and lateral longitudinal, and obscure transverse ventral folds; of 

 extremities colourless, clean and fairly smooth. First cervical 

 with three prominent swellings, two lateral, one sub-ventral. 

 Corona (32), just wider than collar, (28^) ; sulcus narrow; upper 

 lip, a prominent, undivided lobe. Mastax scutelliform, rami (15), 

 formula, -| to §. Foot of four joints, the first with distinct boss. 

 Spurs moderately short (7) and acute. Toes, three. Food 

 moulded into pellets. Maximum length (211). 



A robust little form, whose colour, shoulder swelling?, pro- 



