HARRIS : CRAYFISHES GKNUS CAMBARUS. 115 



dimentary. The antennse are reproduced, well formed, and of 

 about their full length, though the one on the left side is not 

 quite as long as the other." 



''From these observations it will be seen that the parts, such 

 as the legs and antennse, are not reproduced in perfection on 

 one shedding of the shell, but each time the shell is cast they 

 are more nearly perfect than before, and that in this instance it 

 has taken three moltings, one before the animal was captured, 

 to bring the great claw nearly to its full size, and one more 

 molting, at least, will be necessary in order to perfect this im- 

 portant member. The posterior legs, on the contrary, are per- 

 fected in two moltings, and in this case in about five months 

 from the time they were lost. The antennse are developed 

 more rapidly and approach their full size in one molting, and re- 

 produce lost portions in less than three months. Since its cap- 

 ture the animal has not increased perceptibly in size. . . ." 



It will be noticed that the specimen exuviated two times 

 within three months. "This milk-white specimen of C.pellu- 

 cidus has not changed color after shedding its shell twice and 

 living in the full light of da}^ and often for hours in the sun- 

 shine, for over five months. Between the two exuviations it 

 fed not more than three or four times, and then upon only a 

 small quantity of food." 



In conclusion he says : " It is also interesting to record that 

 extremes of temperature do not effect these crayfish from the 

 cave, as my several specimens have several times been retained 

 in a heated room, and again have been exposed for weeks to 

 such intense cold as to freeze the water in their jars," 



In a foot-note added at the time of going to press, nearly ten 

 months after the specimens were taken, he says : "Another 

 specimen of the blind species, of about the same size, is still 

 alive, and has been exposed to full light of day since last No- 

 vember, has eaten but very little, and has not shed its shell. 

 The small specimen of C. hartonii mentioned above as hav- 

 ing molted [about February 20J has not increased in size nor 

 changed in color since February, and is apparently in good 

 condition." 



In reference to the change of color upon exuviation, he found' 

 that "the young specimen of C. hartonii had the same color- 

 after shedding as before," and that the theory that the grayish 



