HERMAPHRODITE. 275 



larger than the others,) a rostrum, sub-rostrum, sub- 

 carina, and three pair of small latera. All the valves are 

 covered by membrane, as are the calcareous scales on the 

 peduncle ; and this membrane everywhere is densely 

 clothed with spines. The upper valves are not very 

 thick ; they stand rather close together. The eight valves 

 of the lower whorl are more solid, and are placed far 

 apart; they are small, tending to become rudimentary. 

 None of the valves are added to at their upper ends, in 

 which respect this species differs remarkably from the 

 others of the genus, and approaches in character to 

 Pollicipes. 



Scuta, with a deep hollow for the adductor muscle, 

 triangular, with the basal margin elongated, and pro- 

 tuberant. 



Terga, large, flat, triangular, basal point blunt, with 

 the carinal margin slightly hollowed out, and the scutal 

 margin protuberant. Apex solid. 



Carina, rather longer than the terga, straight, gradually 

 widening from the upper to the basal end, deeply concave. 

 In young specimens the upper part is slightly bowed 

 inwards. Apex solid. 



Sub-carina, with the inner surface crescent-shaped; 

 the umbo points transversely outwards ; in width it 

 exceeds the largest of the latera. 



Rostrum, triangular, internally (fig. 8 a) concave ; basal 

 margin slightly hollowed out, and deeply notched ; rather 

 less in width than the carina; short, with the umbo 

 pointing upwards and outwards. In young specimens 

 the apex curves a little inwards. 



Bub-rostrum, with the inner surface transversely elon- 

 gated (fig. 8 b), slightly crescent-shaped, about two thirds 

 as wide as the rostrum. The apex points transversely 

 outwards. 



Latera, three pair ; the middle pair apparently corre- 

 sponds with the upper latera of the other species of the 

 genus. The two other pair of latera, together with the 

 rostrum and sub-carina, form a whorl. The sub-rostrum 



