158 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



hand, however, is not uncommonly seen among" true Leucosidea, 

 such as Xursilia dcntata and Myrodes eudactylns, for instance. 



Bell does not include the Iphicidns in his "Monograph of ihe 

 Leucosidas," although he states that it is "most probably associated 

 with them."^ 



From the structure of the maxillipeds and other important parts, 

 this crab seems evidently allied to Iphis and Orcophorus. Its cara- 

 pax is indeed much broader than in any other Leucosidian genus, the 

 front is not all produced, and the epistome is quite large ; but the 

 spines of the carapax are much like those of Iphis, though differing 

 in number and position. This is best shown wdien the body is 

 denuded of pubescence, as in pi. xviii_, fig. 8a. 



With regard to the mouth parts we may observe the following 

 points : The mandibles resemble those of Iphis, but the apex of the 

 corona is obtusely rounded. The maxillipeds of the inner pairs are 

 exactly like those of Iphis. The outer maxillipeds are much shorter 

 than is usual in the tribe, each of them being more than half as 

 broad as long. They are convex, much bending upward anteriorly 

 to follow the curve of the body. The exognath is somewhat shorter 

 than the endognath. and nearly two-thirds as broad ; the apices of 

 these two branches are separated by the inner wall of the pterygos- 

 tomian channel, which here projects strongly between them. The 

 surface of the exognath is sharply granulated at the middle and 

 toward the outer margin, which is straight ; its apex is obtuse. The 

 endognath longitudinally sulcated or divided into two portions, 

 the inner half being depressed and smooth, the outer prominent and 

 granulated; the meros is triangular, less than two-thirds as long as 

 the ischium; the commissure of these two joints is oblique, and 

 angular at the middle. The pterygostomian channels are deep ; the 

 walls at the anterior extremity strongly projecting and arcuated, 

 interrupted at the exterior angle by a very deep notch, rounded and 

 somewhat widened at the bottom, and near the interior angle by a 

 shallower notch, separating the main length of the inner margin 

 from the dilated lobe at its anterior extremity. The anterior margin 

 of the palate is dilated, much projecting at the middle, but not as far 

 as the extremities of the pterygostomian channels. 



The orbits are nearly transverse, but the eyes can be thrown for- 

 ward into a longitudinal direction. 



' Lin. Trans., xxi, 312. 



