ORTMANN : THE CRAWFISHES OF THE STATE OF PENNSYLVANIA 477 
Here males of the first form were abundant. while those of the second form were 
few and small (between 32 and 43 mm. long). The latter consequently all belonged to 
the generation of that year. Some of them very likely would have changed into the 
first form within a short time. The smallest male of the first form was 39 mm. long. 
In addition I have seen specimens from Lake Erie, Lorain County, Ohio (Oberlin 
Museum) collected May 1, 1892, which demonstrate the presence of males of the 
first form in spring, and J have received from Mr. E. B. Williamson a couple col- 
lected September 1, 1901, in Emmet County, Michigan, in the act of copulation. 
The date is slightly ahead of my earliest date for this act in C. obscwrus, but falls 
into the same general season. All these dates perfectly agree with the rules laid 
down for C. obscwrus. 
Of C. propinquus sanborni I have collected material only in the early spring and 
late summer. The specimens observed in spring (April 14 and 28, 1905), in the 
Tuscarawas drainage, Ohio, correspond entirely to the spring condition of C. obscwrus. 
Generally they have a thick coat of dirt, showing that they have gone through the 
winter without moulting. Most of the males are of the first form, but a few are of 
the second form, and these have new shells. A large number of the females have 
eggs. From Dr. Sterki I received a number of newly hatched young, 12-15 mm. 
long, collected on June 18, 1906, at Dennison, Tuscarawas County, Ohio. Among 
the specimens collected on August 28 and 29, 1905, in Wetzel and Pleasants 
Counties, West Virginia, many males of the first form were present, but also a con- 
siderable number of the second form ; besides, there were a number of small speci- 
mens of the generation of that year. Among the material of this form from Oberlin, 
collected September 28, 1903, the same was true, and thus in this form also the 
known facts agree with what has been observed in the case of C. obscwrus. 
3. Cambarus limosus. 
This is the species on which Andrews (1895 and 1904) made his observations. 
My own dates, which are supplemented by those collected by Mr. H. Gera and Mr. 
W. R. McConnell, are comparatively few, but, as far as they go, show certain 
discrepancies with Andrews’ results, which need attention and explanation. 
The largest number of observations I possess are dated in the month of Septem- 
ber, when I collected this species at numerous localities in eastern Pennsylvania, 
New Jersey, and eastern West Virginia in the years 1898, 1904, and 1905. At this 
time the condition of this species entirely corresponds to that of C. obscwrus. Males 
of the first form are abundant and of all sizes. (Smallest, 37 mm. long, from Stony 
Brook, Princeton, New Jersey, September 21, 1898, and 40 mm. long, from Gren- 
