23 



Pcronca varicgana, Schiff. 9-3 



W. Mansbridge. 



Sacculus broad, widely emarginate, edge rugose. Socii 

 broad. Cornuti one rose thorn, eight to nine slender spines. 

 Ostium and operculum minutely spined; lobes wide, 

 rounded. Signum scobinate. 



Pcronca f issurana. Pierce and Metcalfe. 



/. W. M. 22 



Sacculus slightly arched. ^Edoeagus with strong branched 

 spine before the orifice; cornuti one long, slender spine. 



Ostium lobes short, tapered, pointed; ductus bursae 

 clothed with small black nodules. Signum stellate. 



Pcronca rcticulata, Strom. J . W. M. 21 



Sacculus broad, emarginate before half, afterwards rounded 

 to anal angle, which is pointed. Socii narrow, ^doeagus 

 genicnlate. Cornuti three to five. 



Ostium orifice minutely spined, lobes short, pointed, 

 angular. Signum ovate, spined. 



Pcronca lorquiniana, Dup. J. W M. 1 1 



The development here suggests a further removal from the 

 genus 



Sacculus broad, projecting lobe at half; afterwards 

 emarginate. Socii specialised, long ; erect, clothed with 

 spines. Anal tube with narrow neck. Cornuti four spines. 



Ostium naked, simple, operculum minutely spined; 

 lobes curved, sharply pointed. Signum small, scobinate. 



GENUS G. Rhacodia, Hb. TYPE cmargana, Fab. 



Rhacodia cmargana, Fab. l 1 



A development of Peroneidii. 



Valva trigonate; costa thickened; valvula pointed. 

 Sacculus extends upwards to and beyond the costa, then 

 makej a complete hook, terminating in a head of spines. 

 Uncus indent. Anal tube highly chitinised. Socii erect, 



