94 CRUSTACEANS OF THE 



sinuatifrons. The internal portions, bouucling the slightly 

 declivous epigastric lobes, are placed a little in front 

 of and quite separate from the lateral portions; the 

 internal portions are about as broad, taken together, as 

 the free border of the front and are not cristiform, 

 but only rugose and wrinkled. In Pot. sinuatifrons, how- 

 ever, they are more or less cristiform. The lateral portions 

 are cristiform, obscurely crenulate, almost straight; 

 they extend a little beyond the outer angles of the orbits, 

 but stop then abruptly, at a distance of about 5 

 millimetres internally to the epibranchial teeth, at the end 

 of the cervical groove. Between this spot and the epibran- 

 chial tooth one observes four or five rounded granules. 

 The postfrontal ridge is rather far distant from the free 

 border of the front and from the orbits; the distance be- 

 tween the former and the internal portions measures, in 

 the median line of the carapace, 5 millimetres, so that 

 the front is nearly three times as broad as long. Just 

 as in Pot. siiiuatifrons, the trapezoidal epigastric lobes are 

 bounded posteriorly by shallow furrows, but they are less 

 distinct. 



The obscurely denticulate outer margin of the extra- 

 orbital tooth is nearly straight and makes almost a right 

 angle with the contiguous portion of the upper margin 

 of the orbits; this margin has a much more oblique 

 direction than in Pot. sinuatifrons (Fig. 8 and Fig. 9). 

 The extraorbital tooth is slightly concave above and the 

 outer angles of the orbits are moderately sharp ; they 

 reach almost as far forwards as the free border of the 

 front. The epibranchial tooth is also moderately sharp, 

 but small and little prominent; these teeth are 

 placed, just as in Pot. sinuatifrons, a little before the 

 postfrontal ridge, so that a line uniting them passes along 

 the upper margin of the orbits. The epibranchial tooth is 

 comparatively farther distant from the outer angle of 

 the orbits, i. e. the outer margin of the extraorbital tooth 

 is comparatively longer than in Pot. sinuatifrons. The 



Motes from the Leyden IMuseum, Vol. XXI. 



