62 INSECUTOR INSCITL^ MENSTRUUS 



until now remained unknown.^ It may be recalled that Prof. 

 Harold W. B. Moore, of British Guiana, discovered the larvae 

 of this species, which live attached to the roots of the peculiar 

 floating aquatic plant, Pistia. The adult titillans shows much 

 specialization. This, together with the fact that Professor 

 Moore, a most able observer, in a locality where the species 

 abounded failed to find eggs in situations where they were to 

 be expected, led to the conclusion that the eggs are disposed 

 of in an unusual manner. Such has now proved to be the 

 case. 



Professor Moore at our solicitation continued the quest with 

 most remarkable results. He has most liberally placed at our 

 disposal his notes and the accompanying material. His first 

 announcement to us, under date of January 2, 1915, was as 

 follows : 



"You will be glad to know I discovered the eggs of Man- 

 sonia titillans on the 21st of last month. I have also obtained 

 them from a confined female. She sucked my hand at 4 p. m. 

 on the 23d December and was kind enough to oviposit on the 

 night of the 28th. These, as well as clusters found in nature, 

 I shall send forward to you. The eggs are certainly unique 

 and are placed on the under surface of the leaves of Pistia. 

 They are deposited in a mass, generally between ribs of the 

 leaves." 



Details concerning the eggs came in a letter of January 30, 

 1915, and at the same time the promised material. Carrying 

 the investigation a little farther. Professor Moore had brought 

 to light a most unexpected complication. The egg-masses of 

 Mansonia found attached to the under surface of the Pistia 

 leaves were of two kinds, each composed of eggs of a very dis- 

 tinct type, and yet the parents appeared to be alike. In the 

 one kind the thicker or free end of the egg is drawn out into 

 a slender stalk. The other type has a body of similar shape, 

 but the top is drawn out into a short neck like that of a bottle ; 

 from the end of this neck project laterally on four sides as 



^We have already pointed out that the eggs figured for this species by Goeldi 

 (Mem. Mus. Goeldi, iv, 1905, pi. I) are those of a species of Aedes. 



