70 CARCINOLOGICAL STUDIES. 



attributed to the somewhat larger size of the crab of the 

 Berlin Museum. 



The cephalo thorax (fig. 6) is hexagonal, moderately 

 convex in the antero-posterior, and slightly so in the trans- 

 verse direction. Only a part of the regions are indicated. The 

 posterior half of the mesogastric and the anterior half of 

 the cardiac region are defined laterally by shallow grooves, 

 but there is no transverse groove between these two regions. 

 The cardiac region is separated posteriorly from the branchial 

 regions by somewhat erose and uneven shallow impressions, 

 which separate it also from the intestinal region. On each 

 side of the mesogastric region a short impressed line is 

 seen anteriorly, with a punctiform impression at the internal 

 extremity of each line. A shallow depression , bearing two 

 verrucous eminences , separates the hepatic from the bran- 

 chial regions and the latter are somewhat erose and uneven 

 in the middle. The anterior declivous part of the upper 

 surface presents no interregional grooves at all. The upper 

 surface is smooth and glabrous , though it is rather irre- 

 gularly punctate and marked with numerous shallow and 

 small impressions, which give it here and there an erose 

 appearance. 



The cephalothorax is a little broader than long , and the 

 proportion of the distance between the third antero-lateral 

 teeth and the length is about as 4:3. The front is obli- 

 quely directed downward and measures about a fifth of 

 the distance between the posterior antero-lateral teeth. Its 

 rather sharp anterior margin terminates in four small obtuse 

 teeth , the external of which forms the internal angles of the 

 orbits ; the median teeth are placed close together and project 

 a little more forward than the external ones. These frontal 

 teeth are a little more prominent in the specimen of Herbst 

 than in that of Leyden. The front is flattened and smooth, and 

 presents no trace of a frontal furrow. The breadth of 

 the front between the tips of the external 

 teeth is a little larger than the width of the 

 orbits between their inner and outer angles. 



Notes irom th.e Leyden ÜMuseum , Vol. XII. 



