116 ROYAL SOCIETY OF CANADA 



marine^ or perhaps not even adapted to a fresh-water habitat. Its strong 

 limbs seem rather to have been suited for movement on the land. But 

 the thoracic joints appear to have been rigid which would seemingly 

 have been a disadvantage to a dweller on the land. 



BELINUROPSIS n. gen. 



Body of considerable size, trilobed. Head-shield as in Belinurus, 

 except for a pair of notches and spines at the back. Axis of the thorax 

 narrow; pleura long, joints numerous. Perhaps an amphibious animal 

 as it was found in sandy shale with well preserved land plants. 



BELINUROPSIS WiGUDENSis ^ n. sp. Plate I, Fig. 3a to d. 



The parts preserved are the head and part of the thorax, the latter 

 much broken. 



Headshield subtriangular with long genal spines. The front is 

 broadly sub-angulated and the cheeks flaring ; the main part of the head 

 is quadrate behind, and on each half of the posterior margin the head- 

 shield is deeply notched and within the notch on each side of the head 

 is a flat lanceolate-triangular tuberculated spine or flap. The glabella 

 is rounded in front, but somewhat quadrate; it is separated from the 

 front marginal fold by a semi-circular depressed cheekband. The head 

 has a broad doubleur of which a piece on the lower side in front of the 

 glabella is movable, opposite which, on the upper side of the head is a 

 pair of large low apophyses. 



Thorax. The part preserved has a narrow axis of seven ( ?) seg- 

 ments, expanded in front to meet the glabella; it has long pleura to 

 which long spines were attached. One detached pleura is slightly curved 

 and has a deep narrow groove along the median line. 



The p3'gidium is not known. 



Sculpture. The whole test is minutely granulate. The underside 

 of the marginal fold and genal spine are longitudinally striate, but there 

 are scattered tubercles on the upper side. Tlie cheeks are covered with 

 prominent tubercles that extend down on the spines at the back of the 

 head. The glabella has some scattered tubercles, but is mostly smooth; 

 scattered and sometimes densely set tubercles are found on all parts of 

 the thorax, the axis, pleura and pleural spines. 



This crustacean is of the general type of Belinurus. Init differs in 

 its peculiar notched posterior border, the intergenal spine or flap, and 

 the very nan-ow axis to the thorax, which also has more numerous seg- 

 ments than Belinurus. 



1 Aboriginal name of St. John, R., Wigudy. 



