88 G- O. Sars. 



the middle of the rostrum. Lip-plate less broad. Caudal part 

 exceedingly slender, abruptly tapering distally, lower corner 

 drawn out to a narrow lobe, which sometimes is greatly pro- 

 duced and slightly recurved, marginal denticles well defined, 

 numbering from 18 to 20 in each row, no lateral denticles 

 present; caudal claws with a single denticle at the base. 

 Colour clear orange, sometimes changing to blood-red. Length 

 of adult female reaching 0,64 mm. 



.Remarks. — This form, though evidently congeneric 

 with the preceding one, is easily distinguishable by a number 

 of well-marked characters, of which especially the excessively 

 prolonged rostral projection and the form of the caudal part 

 may be named. I have convinced myself as to the identity 

 of the Brazilian with the Ceylon form, by examining the 

 original specimens from which the description was given by 

 Mr. Daday. I am also of opinion that the form recorded 

 subsequently by the same author in another paper as AJona 

 macrorhyncha is the very same species. 



Occurrence. — This form was only observed in 2 

 of my aquaria, both prepared with mud from Itatiba, and 

 it did not occur in any of them in any considerable num- 

 ber, though several female specimens were secured. Male 

 specimens, however, were not found. In habits it agrees 

 with the preceding species, though the movements appeared 

 still slower. The specimens were, moreover, easily recog- 

 nized both by their considerably larger size and their bright 

 red colour. 



Distribution. — If my identification of this form 

 is correct, its distribution extends to 3 different continents, 

 being found in Ceylon, New Guinea and Brazil. 



