452 Transactions of the Society. 



60-70 IX. The lorica, without regarding the spines, is barrel- 

 shaped, broadest in the middle and contracting about equally 

 forward and backward. The anterior spines are straight and 

 parallel, the largest ones about 65 /x apart at their tips. The 

 anterior ventral margin is elevated in the middle, straight sided, 

 with a median V-shaped notch. 



The posterior processes are very thick at the base (30 fi), and 

 taper gradually to blunt points. The opening for the foot is very 

 nearly terminal, the ventral margin a little farther back than the 

 dorsal. The Qgg, which measures 80 yu- by 55 /a, is carried on the 

 dorsal surface of the great curved posterior spines. The slender 

 wrinkled foot ends in two small toes, each bearing one small claw. 



Hahitat. — In very salt water, the lagoon near the Botanic 

 Gardens, Eio de Janeiro ; about a dozen specimens. 



At a first glace it will probably be said that here is our old 

 friend Schizocerca {57) under a new name, and I believe that it is so. 

 But it is Schizocerca without the generic character, viz. the cleft 

 toes. Apart from this, the genus Schizocerca has been discredited 

 by the discovery that a recognized Brachionus (B. angularis) has 

 the same structure of toes. This might be met by the suggestion 

 of removing to Schizocerca any Brachionus with furcate toes. I do 

 not think the character has generic value, or any value. We 

 would not dream of making a new genus for Mo7iostylas having 

 two claws, since this occurs as a sport in some, constantly in other 

 species. 



Even as a Schizocerca, the animal has sufficient specific charac- 

 ters — the unusual development of the median pair of anterior 

 spines ; the presence of the additional, almost rudimentary, spicules, 

 making up the normal six anterior spines of Brachionus ; the great 

 size and upward curvature of the posterior processes ; different 

 form of the foot opening ; and the anterior ventral margin. 



Schizocerca diversicornis var. homoceros Wier. (65), has the pos- 

 terior processes much shorter, and differs, like the type, in all the 

 other points indicated. 



Brachionus falcatus Zach. {66). 



In the salt lagoon at Eio I found a single example of this 

 species. 



Brachionus angularis Gosse {59). Plate XVIII. , figs. 46a to 46/. 



A host of varieties of this species occurred in the salt lagoon 

 at Eio. They varied extremely in size, the contracted lorica 

 measuring as little as 80 /a, the tailed varieties reaching to 280 yu, 

 {B. caudatus Dad. {56) ). 



