CRETACEOUS CRUSTACEA. 271 



region triangular, tumid, corresponding with the lateral angle, 

 and greatest width of the carapace, and defined between the 

 narrow sharply-marked linear nuchal furrow, and an oblique 

 mesO'branchial sulcus, extending from about its middle to a 

 little below the lateral angle of the carapace ; meso -branchial 

 regions narrow, strongly depressed in their posterior half; he- 

 patic regions very large, evenly tumid; pterygostomian regions 

 very tumid ; orbital regions undefined, two notches in the upper 

 edge of each. 



This genus belongs clearly to the true Brachyura, which are so 

 rare in the fossil state, but is distinct from every living or fossil 

 generic type with which I am acquainted. The types of the 

 genus are the following species, and the Podophthalmus Buchii 

 of Keuss (Versteinerungen der Bohmischen Kreideformation, 

 p. 15). 



The reference to the genus Podophthalmus (Desmarest) by 

 Reuss rested upon very slight foundation, as is shown by his 

 remark, that the rare specimen of this little crab which he found 

 " stets mit ihrer Bauchflache fest ins Gestein eingewachsen, 

 so dass sich nur der Riickenschild sehen liess. Auch die Augen 

 konnten nicht untersucht werden. Desshalb ziehe ich sie auch 

 nur mit Zweifel zu der obengenannten Gattung, mit der sie sonst 

 ganz gut libereinstimmt." I have now observed the orbits, and 

 find they completely negative the reference of the fossils to 

 Podophthalmus, for instead of forming extremely long narrow 

 channels, extending to the lateral angle, or widest points, of the 

 carapace, they are small, broad-oval, and the long diameter is about 

 double the short one ; the forms of the various regions on the 

 carapace are also quite different, as well as the general outline, 

 from the great curvature of the front in the fossil, and conse- 

 quent shortness and outward slope of the posterior lateral 

 margin, 



Reussia granosa (M^Coy). See Plate, fig. 4. 



Desc. The general form of the carapace as in the generic cha- 

 racter ; front and anterior lateral margins very strongly curved, 

 so that the lateral angles are on a line with the gastric fossae, 

 the tumid, very slightly angulated edge bearing five or six 

 irregularly placed, small, distinct tubercles between the orbit 

 and lateral angle ; hepatic region much larger than the proto- 

 gastric lobes ; meso-gastric lobe very sharply defined, by deep 

 narrow impressed outlines ; line between the proto-gastric and 

 hepatic lobes very faint ; nuchal furrow as a sharp, distinctly 

 impressed narrow line, extending from the base of the meso- 

 gastric lobe to immediately in front of the second tubercle 



