134 REPOBT 1871. 



means to work out as far as possible the histoiy of this strange freat. He added 

 that they could not be called altogether " tailless ; " docked they may be, from not 

 having a vestige of the external caudal fin-rays. The fish were in splendid con- 

 dition, and the whole of the other fins perfect ; and in every other respect nothing- 

 was wanting, as could be seen by the specimens shown, and by the beautiful ske- 

 leton of one prepared by Mr. Stirling, assistant to Professor Turner*. 



On the Hydrographical System of ilie Freshivater Fish of Algeria. 

 By Colonel Piatfaib. . 



Remarks on a favourable occasion for the estahlishment of Zoological Obser- 

 vatories. ■ By P. L. ScLATEE, M.A., Ph.D., F.R.S. 



After alluding to the report of the Committee of the British Association for the 

 establishment of zoological observatories, which had been read by the author at a 

 previous meeting of the Section, attention, was called to the fact that a veiy favour- 

 able opportimity for the establishment of three zoological observatories in very 

 little-known parts of the globe would shortly present itself, and it was greatly to be 

 hoped that advantage would be taken of it. 



On the occasion of the transit of Venus in 1874, the Astronomer Royal proposes 

 to organize observing-expeditions to the following five stations : — (1) Oahu, Sand- 

 wich Islands, (2) Kerguelen's Island, (.3) Rodriguez, (4) Auckland, New Zealand, 

 (5) Alexandria. At the first three of these stations (Oahu, Kerguelen's Island, 

 and Rodriguez) it would be necessary to have a corps of scientific observers resi- 

 dent for twelve months previous to the transit, in order that the absolute longi- 

 tudes of these places, which were not correctly known, might be obtained. The 

 author pointed out how little was yet known of the terrestrial and marine zoology 

 of these three islands, and specified various particulars, in the case of each of their 

 faunas, which it would be especially desirable to investigate. He then urged that 

 the addition of one or more zoological collectors, or observing-naturalists, to the 

 corps of astronomical observers in each of these stations would occasion very slight 

 additional expense, and suggested that application should be made to the Govern- 

 ment to permit such natm-alists to accompany these expeditions, and to undertake 

 the necessary expenditure. 



Dr. J. A. Smith exhibited the Skull of an Elk found in Berwickshire. 



On the Structure of Crinoids. 

 By Professor "W'tvule THOsrso^'^, F.R.SS. L. &; E. 



On the Pcdceontological Relations of the Fauna of the North Atlantic. 

 By Professor Wyvtlle Thostson, F.R.SS. L. Sf E. 



On a curious South-African Grasshopper, Trachj-pctra bufof (White), ivhich 

 mimics with much precision the appearance of the stones among ichich it 

 lives. By Roland Trimex, F.L.S., F.Z.S. 



_He commenced by remarking that some tendency existed to separate too 

 widely those cases of mimicry where one animal iniitated another, from those 



* Since the paper was read Mr. Peach had learnt that this want of caudal fin-ravs has 

 not been occasioned by lead-poisoning ; for not a particle of lead is to be found in or near 

 the loch. In a loch on the island about 6 miles from Loch Namaorachin trout are found 

 plentiful ; tliis loch is in a Uraestone basin, and lead is abimdant in it ; and here all the 

 trout have perfect tails, and all the other fins in fine condition. 



t Methuen's 'Wanderings in the Wilderness,' 2nd edit. 1848. Appendix, p. 362, pi. ii. f. 3. 



