PELAGIC LIFE, FALMOUTH. 307 



Duriug the calm summer evenings this year, I have 

 frequently observed two species of dipterous insects flying just 

 on the surface of the sea, and also hovering on the rocks forming 

 the Black rock, when left exposed by the tide. After some 

 considerable difficulty I captured a few specimens of both 

 species, but so far I have been unable to identify either. 



Mr. Julien Deby (3) has recorded the capture of a marine 

 dipterous insect at Biarritz, and has named it Psamathiomya 

 peetinata. 



On the 4th of this month one female Monstrilla rigida with 

 ova attached was secured in the tow-net ; and in the same gather- 

 ing specimens of Evadne nordmanii and Podon intermedins 

 occurred in abundance. On the 9th there was a light easterly 

 wind blowing, the surface temperature being 57-9°F, and the 

 tide one hour on ebb. On that morning I worked the surface- 

 net in two places with a view to study what effect the wind had 

 on surface forms. The net on the first occasion was worked 

 across the tide from half way between the Black rock to St. 

 Anthony's point. There was in this gathering a fair quantity 

 of the following forms : — Larvse of Decapod Crustacea, Oypho- 

 nautes, medusiform stage of Obelia gelatinosa, and some common 

 species of various copepods. The net was then worked along 

 the southern edge of the Eastern breakwater, amid the debris 

 blown thither by the wind. In this locality, in addition to the 

 forms above mentioned, I noticed in the gathering a single 

 specimen of Monstrilla and several specimens of the Pteropod. 

 On the 11th, the only interesting specimen noticed in the 

 gathering was a single larval form of Eucratea chela ta. From 

 the 12th to the 17th, the species of Peridinium, recorded in my 

 last report, literally swarmed in the upper portions of Penryn 

 creek. About the 20th, a very interesting species of Infusorian, 

 new to me, was very abundant in the sea in the neighbourhood 

 of Flushing. After a careful examination of several specimens, 

 I have identified it as Prorocentrum micans figured and des- 

 cribed by S. Kent (8.) At this time I had occasion to examine 

 the crystalline style of several specimens of Ostrea edulis from 

 that locality. I was astonished to find imbedded in the 

 crystalline style quantities of Prorocentrum micans ; but I 

 hunted in vain to find a single specimen of Peridinium in that 



