272 BRITISH TYROGLmttD^E. 



G. platygaster, i. e. rough and granular like shagreen ; 

 the male is different, being covered with minute 

 hemispherical bosses or dots, much larger in proportion 

 to the size of the creature, and much rounder and 

 more regular. 



Female. Cephalothorax small, short; about one- 

 sixth of the total length of the creature as seen from 

 above ; conical with curved sides. Rostrum rather 

 obtuse, forming a hood above the mandibles, which 

 project, giving a pointed appearance. The rostral 

 hairs rather thick, far back, stiff, and curved down- 

 ward. Further back, on the dorso-vertex, are two 

 powerful spines directed forward; not springing from, 

 papillae, but almost close to the anterior margin of the 

 abdomen. Mandible (PL XV, fig. 5) short ; each arm 

 of the chela tridentate ; the terminal tooth of the fixed 

 arm bifid. Abdomen large, gradually increasing in 

 width from the anterior to the posterior margin, but 

 with a curved lateral outline; the increase is most 

 rapid in the first third of the abdomen. The anterior 

 margin is almost straight. The hind mar gin is entirely 

 occupied by two great rounded lobes directed backward ; 

 the bursa copulatrix is sunk between them. The 

 notogaster is raised above the cephalothorax ; it has 

 a certain flatness of general appearance, but is not so 

 flat as that of G. platygaster ; its central part is slightly 

 arched, and its lateral edges form bands which are 

 sharply depressed at their inner, and slightly raised at 

 their outer sides. The lobes, which form the posterior 

 margin, are raised; they coalesce, and a broad raised 

 tongue with a rounded anterior end runs from them 

 along the median line of the notogaster for about two- 

 thirds of its length. Along the outer edge of the 

 lateral band on each side of the abdomen are nine 

 singular projections ; the first of these is at the angle 

 of the anterior, the ninth at that of the posterior 

 margin; they are irregular in form, but usually all 

 more or less bifid or trifid ; each one, except the second 

 and sixth, bears a very strong greatly curved pointed 



