REPORT OF COMMISSIONERS OF INLAND FISHERIES. 105 



the nipper type. The tip of the dactyl is broken, but it may be 

 readily seen that its original length must have been practically of 

 the size necessary for normal opposition with the index; this, to- 

 gether with its general form, marks this part of the claw as the 

 original or normal dactyl. 



The extra process D'(R'+L') arises from the toothed border of 

 the dactyl. It deviates slightly posteriorly or outward from the 

 normal plane of motion for the dactyl. The two borders facing the 

 dentate margins of the dactyl and index are both set with pointed 

 "nipper" teeth. When the jaw is closed, however, the dentate 

 margin of the extra process does not meet the index in a normal 

 manner. Each toothed border of this claw is also fringed with 

 tufts of tactile hairs. 



This and specimen No. 4 are in the commission's collection of 

 marine life. No. 2 came from Narragansett Bay off Beaver Tail, 

 and was brought to Secretary Morton on September 5, 1906, by 

 deputy, Mr. T. Luth. 



2. Abnormal Processes arising from the Normal Propodite. 



a. Two Extra Dactyls and Double Extra Indexes. 

 Specimen No. 3, Fig. 3 (Left Chela). 



This curious specimen has been so sadly defaced and deformed that 

 one would hardly recognize it as the cheliped of a lobster. As may 

 be seen in the figure, the normal dactyl (D) and index (I) have been 

 nipped off close to the joint, as the result, no doubt, of some sub- 

 marine combat. The exposed ends of the stumps are covered with 

 a dark-brown blood clot. While there are not enough characters 

 left to determine conclusively the structui-e of the original parts, 

 still, from the general slender form of the stumps and the tufts of 

 tactile hairs (h) at the base of the dactyl, it seems evident that the 

 original claws were of the " nipper " type of chelae. That these two 

 stumps represent the normal index and dactyl is inferred, not only 

 because they are larger than the other similar structures on this 



