ORTMANN: THE CRAWFISHES OF THE STATE OF PENNSYLVANIA 491 
I once observed the change of a male from the second form to the first form. 
The specimen was 58 mm. long, and was dug out of its hole on August 18, 1905, at 
the type locality, Edgewood Park. It was kept in a jar in water, and had moulted 
on August 30. I had been away on an excursion on the two preceding days, but on 
August 27 it had not yet shed. When the fact was discovered it had eaten the 
larger part of its old shell, only the claws remaining, which were also eaten up sub- 
sequently, all but the finger-tips, by September 4. The new shell measured 61 mm. 
in length. When captured this specimen was of the second form. After moulting 
it was of the first form. 
On account of the irregular spawning season it is impossible to trace the life-his- 
tory of one and the same individual, and consequently we cannot draw conclusions 
as to the duration of life. 
The few observations on C. carolinus entirely agree with those made on C. 
monongalensis. 
Males of the second forms were found in May, June, July, August, and Sep- 
tember. For males of the first form I have the following dates: May 17, 1905; 
June 24, 1904; August 2, 1905; August 11, 1904; August 12, 1904 ; September 5, 
1905 ; September 7, 1904 ; October 16, 1905. The smallest male of the first form 
measures 56 mm. in length. 
Two females with eggs were secured on July 12, 1904. One was 80 mm. long, 
and had only three.eggs ; the other was 77.5 mm. long, and had seven eggs. These 
numbers seem strangely small, and apparently are not normal, for on August 1, 1905, 
I found a female 69.5 mm. long, with twenty-two young under the abdomen. But 
even this number is below the average of C. monongalensis. While these cases seem 
to indicate a spawning season in July, the finding of very young ones in the hole of 
the mother at other dates considerably extends this period. I have found such on 
May 17, 1905 (17 to 21 mm. long); June 13, 1905 (14.5 to 21 mm. long); August 
1, 1905 (18 to 25 mm. long); August 2, 1905 (28 mm. long); August 9, 1904 (17 
to 25 mm. long); August 11, 1904 (19 to 29 mm. long). 
The largest young remaining with the mother were 29 mm. long, while the 
smallest in a hole by itself was 30.5 mm. long. Thus the time of leaving the hole 
of the mother is about the same as in C. monongalensis. 
The above observations are not at all sufficient to show that C. carolinus agrees 
entirely with C. monongalensis, but since both species are alike in so many particu- 
lars, morphological and ecological, and since the above dates do not show any differ- 
ences, we may safely assume that the life-history of both species is similar. 
The seasonal history is rather well known in four of the species above discussed, 
