REPORT OF COMMISSIONERS OF INLAND FISHERIES. 109 



United States Lobster Hatchery at Booth- bay Harbor, Maine, 

 where, through the kindness of Prof. F. P. Gorham and Superin- 

 tendent Captain Hahn, I was given an opportunity to study the 

 living specimen. Through the courtesy of Dr. H. M. Smith, deputy 

 commissioner of the United States Bureau of Fisheries, the lobster 

 was later transferred to the experiment station of the Rhode Island 

 Commission of Inland Fisheries, at Wickford, R. I. 



In our description of this extraordinary chela we will begin with 

 proximal segment or ischiopodite (Is). This abnormally large and 

 distorted segment does not readily lend itself to discription; in a 

 general way, however, it may be compared to triangular prism. 

 One of the edges of this prism will then be ventral (v), and the pris- 

 matic surface opposite this edge will correspond to the dorso-lateral 

 face of the segment. This dorso-lateral surface of the segment is 

 also marked by a triangular-shaped scar or indentation (a), which 

 may possibly have been casually connected with the origin of the 

 more distal abnormalities. 



Proceeding to the meropodite, we find that the sides corresponding 

 to our imaginary prism for the ischiopodite are no longer parallel, 

 but diverge very rapidly. The meropodite broadens out distally 

 and finally terminates in two forks or branches (m, m'). The groove 

 between these forks is at a slight angle to the dorso-ventral plane of 

 the normal limb. 



The question now arises which of these two forks is to be regarded 

 as the representative of the normal chela. This can be determined 

 by tracing the continuity of morphological surfaces in a disto- 

 proximal direction. An examination of the surface structure shows 

 that fork m is morphologically continuous frorn the distal extremity, 

 through the ischiopodite to the basal segment or basipodite, where 

 it forms apparently the entire joint with the later segment. On the 

 other hand, the remainder of this compound meropodite meets the 

 part just described more or less of an acute angle, giving one the 

 impression of being grafted upon it. The right fork (m) is, there- 



