Plate XV. 



(All the specimens are in the collection of the Museum of Comparative 

 Zoology at Cambridge.) 



Page. 



Figs. 1-2. Clavilithcs solandcri (types 1061, 27762) 123 



3. Clavi'.ithcs longcevus, a characteristic adult individual (27763).... 126 



(186) 



