342 PAUNA AND FLORA OF THE FALICLAISnDS. 



1 7th and 1 8th we had some beautiful displays of phosphorescence. 

 Mashes of light from two to three feet in length, probably- 

 caused by PyrosomcB were common ; and the whole surface of the 

 sea for some little distance round the vessel was illuminated by 

 countless gleams of light ; some of these being bright green in 

 colour, which greatly added to the beauty of the display. While 

 in this region, I was able to capture a few beautiful specimens of 

 various species of Glolerina ; and on more than one occasion, 

 I was fortunate enough to examine a species of Saliomina with 

 the protoplasm in a partially expanded condition. 



The surface temperature of the sea fell to 77''F. on the 

 evening of the 20th, the position of the ship at noon on that day 

 being lat. 3°47'S., 30°40' W., and with this decrease of tempera- 

 ture, we lost the beautiful displays of phosphorescence we had 

 enjoyed during the previous evenings. 



Birds had been very scarce since leaving Ushant. Some 

 birds, known to sailors as " "Whale birds" [Prion desolatus), had 

 followed the steamer for some days after leaving Santa Cruz ; but 

 with the excejition of a few petrels, probably Procellaria pelagica, 

 and a single frigate bird {Fregata aquila) which hovered round the 

 ship in 16°0'S., 36°47'W., no birds were noticed during the 

 voyage to the South American coast. 



On the morning of the 21st in ll'*25'S. a few veliger larvae 

 were the most interesting forms noticed in the gathering made 

 just before noon. Besides these, a few specimens of a species 

 of Trichodesmium resembling in appearance microscopical bundles 

 of straw, were observed for the first time. 



We all noticed a decided change in the atmosphere on the 

 morning of the 23rcl, the sky being overcast, and the wind dead 

 against us. The sea too, which had been 77" F. at noon in 

 20°4' S., fell to 74" F. at sunset ; the temperature of the air at 

 that time being only 71° F. 



Shortly after noon, in 23*^44' S., the wind fell, and there was 

 a complete calm. As we steamed along, we jDassed through 

 long irregular streaks of discoloured water mostly of a dull-red 

 colour, due to the presence of the species of Trichodesmnim already 

 referred to. According to my observations these streaks of algge 

 varied considerably both in shape and colour ; some being light- 



