1882.] 



On the Coxal Glands of Scorpio. 



95 



by a Carre ice machine. Two carafes were prepared at a time, and 

 there was plenty of time to keep one constantly at hand. 



In order to allow the Miller- Casella thermometers to record the 

 high temperature of 50 fathoms in the last series, they were lowered 

 very rapidly to that depth, and after eight minutes reeled back at the 

 rate of 200 fathoms per minute, so that the minimum side had not 

 time to assume a lower temperature. 



The cable was led from a large reel through an 18-inch leading 

 block, and was lowered and reeled in very slowly, and without jerks. 



It may be noted in the above Tables that the two instruments gave 

 precisely the same readings at positions of maximum or minimum 

 temperature, but that in intermediate positions the electrical thermo- 

 meter, in almost every instance, gave a higher reading. This dis- 

 crepancy may be accounted for, I think, by the circumstance that the 

 electrical thermometer gives the temperature of the water actually 

 surrounding the coil at the moment of observation, whereas the 

 reading of the Miller- Casella instrument must be affected by the 

 maximum or minimum temperatures encountered in its ascent or 

 descent, which may not coincide with that at the points of stoppage. 

 A strong argument in favour of the electrical instrument for geodetic 

 and meteorological purposes has thus been furnished. 



V. " On the Coxal Glands of Scorpio hitherto undescribed and 

 corresponding to the Brick-red Glands of Limulus." By 

 E. Ray Lankester, M.A., F.R.S., Jodrell Professor of 

 Zoology in University College, London. Received May 25, 

 1882. 



In my essay entitled " Limulus an Arachnid,"* I have mentioned 

 Dr. Packard's discovery of the "brick-red glands " of Limulus, 

 situated at the junction of the coxse of the prosomatic limbs with 

 the body in the following terms: — "It is true that Packard has 

 assimilated a brick-red coloured structure occurring at the base of the 

 cephalothoracic limbs of Limulus to a shell-gland or renal organ. 

 In this I cannot agree with him. It is not even apparent, at present, 

 that this brick-red organ, which I have examined, is of a glandular 

 nature at all." 



Dr. Packard first described these glands in 1874, and figured them 

 subsequently in his valuable memoir on the "Anatomy, Histology, 

 and Embryology of Limulus Polyphemus," published in the Anni- 

 versary Memoirs of the Boston Society of Natural History, 1880. 



* " Quart. Journ. Micr. Sci.,7 1881. 



