No. 447] BREEDING HABITS 01- CRAY 



ance of males arose, whether before or afl 

 males have now two pairs of very consijiciio- 

 sexual pleopods of great size ; the exterior 

 and the posterior pair a little more than /. the 

 fish, but this ratio is the same in the adult 

 males the antennae often look longer and nic 

 the females and that this may now be a sec^ 

 acter would seem to follow from the measure 

 males with perfect antennae averaged 50.75 

 their antennae were 42.875 mm., or 847;, < 

 body. The five females averaged 47 mm. 

 antennce 31.4 mm., or hardly 67% of the Icn 

 Under such conditions the young of 6". affr 

 a length of two inches in their first summer 

 for knowing their rate of growth were obtain, 

 hatched about June ist, 1901, from eggs la i 

 young were kept in a large sink with running 

 plants and anodons which dying from tr"" 

 gave them food material. The twenty su 

 February nth, 1902, or 8i months after 

 lengths and widths as well as the sex are 

 The sexes could be readily determined as ■ 

 spicuous annuli and the males well ilevcio] 



Number 4 may have been introduced 

 range in length from 44 23 mm. wil 

 None are as long as two inches : one hal 

 80% above 29 mm. The sexes were a 

 10 males and 9 females. 



These young did not attain to as lai 



