4 U.S. NATIONAL MUSEUM BULLETIN 2 78 



As stated above Mayer used the mandibular palp as a generic 

 character. Those capreUids which lack a mandibular palp such as 

 Caprella have considerably more setation on the mouthparts, antennae, 

 and gnathopods 1 . This increase in setation could compensate for the 

 loss of the cleaning abiUty of the mandibular palp. Very little is known 

 of the dietary habits of those forms which bear a mandibular palp and 

 only a little more is known of those that do not. The setal formula for 

 the palp refers to the number of long, intermediate, and short setae on 

 the terminal article. For example, the setal formula 1-x-y-l indicates 

 the presence of 1 long seta at either end of a row of a variable number 

 of short setae (x) and also a variable number of intermediate setae (y). 



In addition to the mandible the maxiUiped also offers some ne- 

 glected characters which may be of generic significance. The distal 

 margin of the inner lobe varies in shape from rounded to flattened 

 and may bear a variety of tooth types, spines, and setae. As examples 

 of the extremes of inner lobe diversity, the paired inner lobes of 

 Phtisica and aUied genera are as large as the outer lobes, almost com- 

 pletely fused, and are armed mth several unusually large teeth (fig, 

 47h) while the inner lobes of Paracaprella are much smaller than the 

 outer lobes, not fused, and bear only a few setae (fig. 43e). 



The outer lobe of the maxiUiped shows considerable variation in 

 spination, serration, and setation. Such characters as the subterminal 

 notch in Luconacia (fig. 35d) or the large serrations on the medial 

 margin in Mayerella (fig. 37e) may have generic importance. However, 

 in too few of the caprelHd species have maxiUipeds been adequately 

 illustrated and described to permit evaluation. 



The palp of the maxilhped offers several characters which may 

 possibly be of generic significance. Schurin (1935) used the reduction 

 of the dactylus as one of the characters to separate his new genus, 

 Eugastraulax, from the genus Caprella; however, the value of this 

 character is questionable. In Paracaprella and Deutella the distal end 

 of the terminal article bears several large setae (fig. 43e). These large 

 setae are not present in most other caprellid genera. Another character 

 which may have generic importance is the presence of a distal pro- 

 jection on the penultimate article as in Paracaprella (fig. 43e). 



The number of spines on the outer lobe of maxilla 1 varies among 

 some genera. In Phtisica there are 6 spines (fig. 47f) whereas in Caprella 

 there are 7 spines (fig. 8e). Again it is regrettable that this character 

 has not been examined in enough genera to comment on its value, 



Gnathopod 1 has several characters which may be of generic or at 

 least specific value. In the western Atlantic species, the number of 

 grasping spines on the propodus varies from 1-5 (compare figs, 38d, 

 8h, 47c) and seems to be fairly constant within each genus. Another 

 character of gnathopod 1 which may prove to be important is the 



