78 E. A. ANDREWS. 



is in some sort an imitation claw. On both dactyl and index is a 

 long series of transverse plates closely crowded together and 

 freely projecting to give the serrated appearance noticeable under 

 a low power. Each plate is itself serrated near its tip but these 

 fine serrations are seen only with a higher power. As these 

 plates stand nearer to the posterior than to the anterior face of 

 the claw, they are more readily seen from a posterior view. Each 

 plate, like these in Fig. 4, stands obliquely transverse and is 

 shaped like a scalene triangle with bluntly rounded apex. It is 

 just below this apex that the outer and distal edge bears a series 

 of sharp teeth. This fine serration is on the edge that faces pos- 

 teriorly as well as distally and the plates overlap one another so 

 that the teeth could not be seen from an anterior view, such as 

 Fig. 2, were it not that the plates are so transparent that the 

 teeth can be seen through the next overlapping plate. Each 

 plate has a central canal that passes from the epidermis through 

 the length of the plate and ends at the surface in the blunt apex : 

 it passes by the serrations without any connection with them. 

 Morphologically these plates seem to be flattened setae or hairs. 

 In this claw there are 61 plates on the dactyl and 67 on the index ; 

 three or four are broken. As seen in Fig. 2 the series of plates 

 is longer on the index where the proximal six or seven plates are 

 opposed by a bare space upon the dactyl. With this exception 

 the plates of the index and dactyl correspond, each plate having 

 its duplicate in the opposite series. 



In the pronged structure there are two series of serrations show- 

 ing this same symmetry ; some of each series are represented in 

 Fig. 4. 



To save space the two series are drawn as if close together 

 while in reality the rigid prongs always held the two series far 

 apart (Fig. 2). The plate marked T is about the thirty-fifth one 

 from the tip of the prong that has a perfect terminal spine. The 

 edges with teeth are those nearer to the tip and also those farthest 

 away from the serrations of the opposite series. 1 The edge turned 

 toward the plate of the opposite series is smooth and free. The 

 third edge of the triangular plate is the line of attachment and is 



1 The use of these serrated plates may be to aid in cleaning the animal rather than 

 to aid in preparing food by acting against the opposed series ; they may be like the 

 combs on the legs of certain birds. 



