Narrative of Bahama Expedition. 155 



JNIonthly Magazine" for October, 1893, though my sketches, made on the 

 spot, show sharper angles at all the knee joints. The same position is not 

 always maintained, however, h\- different specimens. 



The movements of a tired specimen were as follows: In making a stroke 

 the middle legs were brought forward until the tips were about on a line 

 with the head. They were then rapidly brought back so as to nearly 

 touch the tips of the hind pair, which were moved comparatively but little- 

 The posterior feet seem to lie used to steer with rather than as an aid in pro- 

 gression. The four legs work in unison, not alternately, /. c, the middle legs 

 keep time with each other and with the hinder pair. The tips of the legs 

 rest on the water, and are not immersed in it so that the little hollows near 

 each, caused by the \\ eight of the insect, can plainly' be seen. \\'ith cap- 

 tive specimens sunliglit acted as a stimulant, and e\oked acti\ity, which 

 was lessened by shade. 



One Halobatcs \\as then placed in a tightly corked bottle, filled, when 

 Immersed, so as to make certain that no air was enclosed, except the thin 

 film which invested the insect. This was done at 1:22 i'. m., and at 1:30 

 was witnessed what was then supposed to be the iinal struggle with death; 

 after the expiration of four minutes this recommenced, and was continued 

 at irregular intervals until 1:43, after which no more were seen until 1:48 

 at which time a tiny bubble of air made its way from the cork, and at ] 158 

 another of these bubbles e\oked a feeble struggle, the last. When finally 

 remo\ ed to the alcohol bottle, not a movement could be detected, and the 

 insect was undoubtedly drowned. Ihis would appear to antagonize the 

 theory that they stay beneath the surface in stormy weather. I also 

 noticed, with several specimens, that they could (or \^ouldr) only dive after 

 being wet so that "skimming" was impossible, but this does not agree with 

 the observations of other naturalists, and I recognize its practical worthless- 

 ness as purely negative evidence. 



This was by far the richest tield for Crustacea that we 

 rencountered durin"; our work. The Brachyura were, as 

 usual, the most abundant forms and a never-faihng source of 

 interest to the students, who were constantl}^ discovering some 

 grotesque shape or special protective modification. Between 

 forty and fifty species of Brach}'ura were secured here, hardly 

 a haul coming up without its quota. This collection \\ill be 

 systematically treated in a forthcoming report by Miss Mary 

 J. Rathbun. of the Smithsonian Institution, and it is to hef 

 kindness that the identification of these forms is due. By far 

 the greater number belong to the Maioid group, commonly 

 called •• sea-spiders."' Three species of Podochela were found, 

 the first, P. gracilipcs Stm., having the first true walking leg 

 very greatlv lengthened, being about twice as long as the 



