1875.] 19 [Putnam. 



The great claw of the right side is now very nearly as large as that 

 of the left. The tip of the third leg of the same side is fully per- 

 fected, and all the legs that were rudimentary before are now devel- 

 oped, apparently to their full proportionate size, with the exception 

 of the last on the right side, which is not quite perfect, the two 

 terminal joints being somewhat rudimentary. The antennae 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 antennae, are not reproduced in perfection on one shedding 

 of the shell, but that each time the shell is cast they are more nearly 

 perfect than before, and that in this instance it has taken three 

 moul tings, one before the animal was captured, to bring the great 

 claw nearly to its full size, and one more moulting, at least, will be 

 necessary, in order to perfect this important member. The posterior 

 legs, on the contrary, are perfected in two moultings, and in this case 

 in about five months from the time they were lost. The antennas are 

 redeveloped more rapidly, and approach their full size in one moult- 

 ing, and reproduce lost portions in less than three months. Since 

 its capture the animal has not increased perceptibly in size, and on 

 measurement to-day is still not quite two and one-half inches in 

 length, measured as before. 



It is also interesting to record that extremes of temperature do not 

 affect these crawfish from the cave, as my several specimens have 

 been a number of times retained for days in a heated room, and 

 again have been exposed for weeks to such intense cold as to freeze 

 the water in their jars. 



Note. At the date of going to press, Aug. 7, 1875, all but two of the above 

 mentioned specimens retained in my possession have died from various causes, 

 principally due to neglect in changing the water in their jars. The female, 

 C. pellucidus, mentioned as having shed her shell twice, died June 10, without 

 doing anything worthy of further note. Another specimen of the blind species, 

 of about the same size, is still alive, and has been exposed to the full light 

 of day since last November, has eaten but very little, and has not shed its 

 shell. The small specimen of C. Bartonii, mentioned above as having moulted, 

 has not increased in size nor changed in color since February, and is appar- 

 ently in good condition. 



