426 PLAGIOSTOMATA OF THE PACIFIC, 



I found the temperature (the thermometer lying in the cavity 

 for over ten minutes) 26° 95 C. (about 80° F.) To be 

 quite sure, and to prevent any mistakes, I introduced again the 

 thermometer into the abdominal cavity in half an-hour's time, and 

 let it remain there for over fifteen minutes. 



The very sensitive thermometer (made for observation of 

 temperature of the human body on the sickbed) showed again 

 the temperature of 26° 65 C. (about 79° F.) Wishing to be quite 

 sure about the observations, I induced Mr. R. T. Steiger, the 

 Government Analytical Chemist in Brisbane, to place his ther- 

 mometer in the cavity, and we obtained there with this other 

 thermometer a temperature of 78° F., (or 25° 5 C), which result 

 agreed very nearly with the previous observations. 



Taking the average of these three observations, we find the 

 mean temperature of the body of the Echidna hystrix to be about 

 28° C. (or, 82° 4 F.) 



Comparing the same with the mean temperature of Mammalia , 

 which is, after Dr. J. Davy's observations of thirty-one different 

 species, 38° 4 C, or 101° 10 F., we find that the mean temper- 

 ature of the Echidna is about 10° C, or 19° F., lower than the 

 former. 



I have to add that in the month of July the Echidnas appeared 

 to be in a very sleepy state, moving about in the day time only 

 when disturbed. It is possible that during the winter months the 

 Echidna is subject to a state of hibernation, which may also to a 

 certain extent depress the usual temperature of the body. 



Plagiostomata of the Pacific. 



By N. de Miklouho Maclay and William Macleay. Part 2. 



Plate xx. 



It is now exactly five years since we read a Paper with the above 

 heading at a meeting of this Society, and which was published in 

 the third volume of our Proceedings. 



