72 Miscellaneoiis. 



MTSCELLAXEOUS. 



Descriptions of a neiv Genus and two new Species of African 

 Freshwater Crabs. By Mart J. Rathbun. 



The crabs described below were found in mud under boards and 

 timbers by Mr. J. H. Camp at Stanley Pool, Congo, AVest Central 

 Africa. 



Family Thelphusidse. 



Parathelplmsa Campi, sp. n. 



Carapace subquadrilateral, conspicuously punctate. Depression 

 between tbe gastric and cardiac regions deep. Protogastric lobes 

 prominent, separated by a median groove which extends backward 

 from the frontal margin. The postf rental crest begins behind the 

 base of the eyestalk and is continued to the lateral margin ; it is 

 finely denticulate and is almost straight, sloping backward and 

 outward. Front a little more than one third the width of the 

 carapace, dellexed, divided by a very shallow sinus into two lobes, 

 with a raised margin, which is continued to the ])ostfrontal crest. 

 Superior orbital margin sinuous, advanced in its middle portion. 

 Postorbital tooth acute, prominent. Lateral branchial spines 

 three. In one of the two specimens there is a spinule between the 

 first and second spines and a short fourth spine on the left side. 

 Between the first spine and the postfrontal crest there are two or 

 three spinules, forming a short ridge in the same line with the 

 postfrontal crest. From the last spine a raised line extends back- 

 ward upon the carapace, and is followed by several broken parallel 

 lines. The inferior margin of the orbit is rather deeply rounded 

 below the outer angle ; from that point the margin is directed 

 inward and forward ; the inner angle is obtuse ; the margin is set 

 with a row of bead-like granules. The terminal segment of the 

 abdomen of the female is subtriangular and the length is nearly 

 half tbe width. The raerus of the maxillipeds is very transverse, 

 the antero-external angle rounded, the antero-internal angle not 

 deeply cut. 



Chelipeds of female unequal ; merus rugose above, inner margin 

 tuberculous, with a sharp spine just below the margin ; carpus 

 with two spines on the inner margin. Hand slightly inflated; 

 upper margin straight, lower slightly convex. Fingers irregularly 

 toothed and almost touching. Ambulatory legs rather slender, 

 flattened; propodal joints indistinctly spinulous on the margins. 



Meas\(rements (No. 18065, two females). — Length of larger speci- 

 men 21*5 millim., width 29*5 ; length of smaller specimen 19, 

 width 27. 



This species in its three lateral teeth resembles P. jjcecilei, 

 A. Milne-Edwards, but differs from that species in its narrower and 

 more quadrate carapace and interrupted postfrontal crest. 



Erijietopus, gen. nov. 

 Carapace arcuate anteriorly, quadrate posteriorly, moderately 

 convex. Front advanced beyond the antennular cavities, composed 

 of two distinct rounded lobes. Orbits narrow ; eyestalks tapering 



