390 AN • K - BROOKS ON THE LIFE-HISTORY 



special design in it. than the oft-repeated pulsations of Thaumantias, and each, instead 

 of driving the animal directly forward toward the point whither its whole course tends, 

 propels it in a direction crossing that line diagonally, like the course of a ship in tacking 

 or traverse sailing. It is thus propelled first to one side of its course, and then to the other; 

 il- actual track being a zigzag. * * * This is the motion of Turritopsis when per- 

 forming a long journey, hut he may be often seen sporting about the surface, taking a 

 few sidelong leaps like those described, and then, with the mouth of the bell downwards, 

 expanding himself to the utmost, all his tentacula, which in progression w ere tightly curled 

 up, now gradually disentangling and stretching themselves to their greatesl length, 

 turned upwards or horizontally, while the motionless parachute slowly sink> to the bot- 

 tom (See PI. 37, figs. /and A'). However, the tentacula thus extended seem to he keenly 

 alive to every passing particle, and every now and then, one or two or more of them 

 may be seen to contract with great rapidity, as it they had come in contact with some- 

 thing to be seized or avoided. At this time the Turritopsis has spread all his snares, and 

 bis tentacula radiating on all sides, form a circle prohahly equally efficacious with the spider's 

 web. Indeed I have found small Crustacea, their principal food, frequently dead or dy- 

 ing in the emhrace of these tentacula, or rather simply hanging to them by invisible 

 attachments, illustrating in another instance the deadly properties of these wonderful 

 thread-cells. After, however, the Turritopsis has been sinking for some time (he may 

 even allow himself to touch the bottom of the jar), he suddenly draws in, more or less, all 

 his tentaculse, and beats up again toward the surface in the same old zigzag way, now 

 and then running along for a little distance in a horizontal direction, but generally going 

 quite up to the surface, and then expanding himself, mouth downwards, again to sink 

 slowly towards the bottom. The animal may continue fishing in this way a whole 

 morning." 



As it is a hardy species it thrives perfectly in an aquarium, where its active movements 

 and the graceful curling and unfolding of its long hair-like tentacles, as well as its brighl 

 color, render it very attractive. A spechnenmay, if supplied with proper food, be kept 

 all summer, but it is very voracious, and I have seen a small specimen kill and finally 

 swallow a Sagitta more than half an inch long, the Sagitta being bent like a bow in the 

 middle and distending the whole body of the Turritopsis. 



At Beaufort a few specimens may be found throughout the whole summer, but it is not 

 very abundant inside the inlet until the end of August, although we frequently obtained 

 great numbers outside in June and July. W hen the south wind, which blows almost con- 

 stantly during these months, comes to an end, near the end of August, Turritopsis makes 

 its appearance inside the harbor, and with the continuance of calm weather, it becomes 

 more and more abundant, and through September and October hundreds of specimens 

 of all ages and sizes may be captured nearly every day. I infer from this, that the hy- 

 dra lives in deep water offshore, and that the proper home of the medusa is in the open 

 ocean. Indeed, we have taken them at the bottom outside with the trawl, at times when 

 the water was so rough that none were found at the surface or inside the inlet. I have 

 found only a single colony of the hydroid, and this was obtained inside the harbor. 



