TRANSACTIONS OF THE SECTIONS. 97 



as E. lividus and E. neglectus, are well supplied witli a deep purple colouring-matter, 

 which gives a beautiful tiuge to the spiues, which is not removed upon boiling in 

 strong ley. The pedicellariae imder these circumstances also possess the purple 

 tint of the spines, the colouring-matter existing in some sort of combination with 

 the crystalline carbonate of lime. These coloured objects remind one of brilliant 

 sapphire gems, profusely decorating the wondrously constructed Echinoderm, less 

 costly and far more elegantly cut than the far-famed jewels of Her Majesty, but 

 destined to be hidden in the dark abyss of ocean's depths, until brought to light by 

 the researches of the naturalist, and rendered evident by the lenses and mirrors of 

 the microscopist. When it is desirable to examine the movements of these organs, 

 it is advisable to remove a portion of a living animal, and insert it in a small 

 trough of sea- water, and watch the pedicellariie mth a low-power objective upon the 

 stage of the microscope. But when it is only desired to examine the structure of the 

 pedicellariffi, it is better to remove the organ with a scissors or small forceps, and 

 having placed it on a slide with a small quantity of glycerine containing a little 

 caustic potass, shortly the musculo-membranous indusium becomes transparent, if 

 not dissolved, and all the calcareous elements become apparent, but stiU not suffi- 

 ciently clear for photographic purposes. Under these circumstances, it is necessary 

 to boil up each animal in distilled water containing a tolerable quantity of caustic 

 potass, which dissolves all the fleshy coverings, and the calcareous pieces are 

 made clean and transparent ; in many instances, if the boiling has been care- 

 fully stopped at the proper time, the two or three blades constituting the forceps- 

 like appendage remain in conjunction, and are then very much more instructive 

 preparations to the microscopist. In order to remove these pedicellariee from the 

 other calcareous debris of the Echinoderm, it is necessary to allow all matter to 

 subside, and decant the supernatant alkaline solution ; and, having removed all 

 traces of potass by frequent washing and subsidence with successive portions of 

 distilled water, it only remains to agitate the whole well together with a steady 

 circular motion, and, after some moments' repose, pour ofl" the supernatant water, 

 which contains the pedicellarial blades in suspension ; on repose, these subside, 

 and may be then removed by a dropping-tube, placed on a slide, dried, and 

 mounted in Canada balsam in the usual way. The objects now exhibited in 

 photographs have all been so prepared by the author himself, and are, conse- 

 quently, authentic specimens, and have all been photographed to one scale for 

 comparison with the same lens and camera. They are under the same identical 

 circumstances in each particular case, so that relative size may be taken into 

 consideration as one of the elements of difference. The writer then went on to 

 describe the different specimens of which he exhibited photographs, many hundred 

 examples of which were prepared for comparison. 



On the Genus Synapta. By W. Bied Herapath, M.D., F.R.S. L. 6f E. 



Having shown the paucity of information which existed in this country on 

 the Synapta, the author next proceeded to refer to descriptions which had been 

 given by different scientific men. M. Quatrefages, he said, had described a Sy~ 

 napta which he had foimd on the shore of the Chanssey Islands, a point off" St. 

 Malo, on the French coast, in the Channel, and he had entered minutely into the 

 anatomy and physiology of the animal, and his paper was most exhaustive of the 

 subject. There was also an admirable paper by Messrs. Woodward and Barrett on 

 the Synapta diyitata and Synapta inhcerem in the Quarterly Journal of the Zoological 

 Society for 1858. Other authorities mentioned by the author were Professor 

 WyvUle Thompson and M. Gallienne. The latter had, in the autumn of 1863, 

 when he was in Guernsey, kindly shown him the locality and mode of finding a 

 Synapta, which he thought to be inhmrens, and had discovered in Bellegrave Bay, 

 on the coast of Guernsey. Having visited the spot where M. Gallienne had 

 obtained his specimens, they found several, a little below low-water level at 

 spring tides, in a bed of sand about ten or twelve inches deep, and congTegated in 

 a space about twenty yards square, whence they were easily obtained by digging 

 cautiously with a spade, the operator being guided in the task by the appearance 

 of the funnel-shaped openings in the sand, mai-king the position of their burrows. 

 On inserting the spade and elevating it quickly, the sand generally cracked 



1864. o -x J, 7 



