1894,] Entomology. 85 
speed quite sufficient to stem a current of two or three knots per hour. 
They seem to like the sunshine and were much scarcer 
when it was overcast. A heavy swell, provided the weather is quite 
calm, does not prevent their appearance, but with the ripple caused 
by the slightest breeze they vanish at once. * * * Ihave kept 
the Chinese species alive for several days in a vessel of sea water, at 
first they are very restless, rushing about and occasionally jumping up 
two or three inches from the surface, but after a few hours they be- 
came much quieter. They then rest on the water with the legs widely 
extended, and the intermediate pair brought forward so asto have the 
tarsi in advance of the head. On the approach of a pencil or the 
finger they dive readily, and swim with great facility beneath the sur- 
face, the air entangled in the pubescence giving them a beautiful ap- 
pearance like that ofa globule of mercury or polished silver. This 
supply of air must be essential to the existence of the insects, which I 
feel sure must pass a large part of their life beneath the surface of the 
sea, diving into undisturbed water in rough or even moderate weather, 
and coming up again only when it is absolutely calm.” 
Mr. Walker is unable to add anything to our knowledge of the feed- 
ing habits of these bugs. “ The union of the sexes takes place on the 
surface of the sea, and the eggs are unquestionably carried about by 
the female attached to the extremity of the abdomen for some time 
before she parts with them.” _ Two females of H. Wulderstorffii were 
taken from the Marquesas Islands with eggs thus attached. The eggs 
are large for the insect, cylindrical with rounded ends, and ochraceous 
yellow. Where they are finally deposited he did not observe though* 
in a subsequent note attention is called to Witlaczil’s record of the 
finding of a bird’s feather at sea covered with the eggs of Halobates. 
Pupation of Gyrinus and Dineutes.—Mr. H. F. Wickham 
continues his studies of the early stages of North American Coleo- 
ptera, his latest contribution’ including descriptions of nine species. 
He describes the larva of Gyrinus picipes as pupating in mud cells 
without any intermixture of silk. “Probably the larva uses any 
readily accessible matter in the formation of its cell and when under 
stones would use mud, while if under bark might utilize wood or bark 
fibre, thus giving the ‘ cocoon’ a papery consistence.” The pupation 
of Dineutes assimilis is described thus: “ The larvee on coming out of 
the water repair to the under surface of a stone or a board close 
ile. p. 252. 
Bull. Lab. Nat. Hist. Univ. of Iowa. Il, pp. 3880—34, pl. IX. 
