( xxvii ) 



to be regarded in all instances as attached to the hyjjopygium, while the two 

 spiculge of the terebra are connected with the epijiygium. Here, however, 

 these five component parts are all associated with the same segment, as 

 clearly defined by a new dissection of Halticella exhibited to the meeting, 

 and represented in the annexed woodcut (whereof copy has been sent to 

 M. Andre), which parts are also shown in their natural position together 

 with this segment, and as withdrawn therefrom, in Sir Sidney Saunders' 

 former dissections ; the first represented in figure 3, and the second in 

 figure 11 of Plate XII., 1882. 



Hence it would seem ttiat the loiver j)ortion of this contested segment 

 must inevitably be regarded as the true hypopygium, accurately corres- 

 ponding with M. Andre's aforesaid description as such ; while the upper 

 portion, as indicated by a longitudinal lateral line sufficiently apparent, 

 would retain the two spiracles and the basal attachment of the spiculae to 

 the dorsal region, which may possibly be assignable to the epipygium ; in 

 which case the two tegumentary fragments adverted to by M. Andre would 

 constitute integral parts of a 6th rudimentary and concealed ventral 

 segment, while the true epipygium and hypopygium would be connate 

 together in this one terminal segment representing the dorsal a;nd ventral 

 portions of the 7th. Under the peculiar circumstances, however, of this 

 terebral-bearing segment becoming ostensibly pseudo-dorsal at its f)rojecting 

 apex, such abnormal character would scarcely be enhanced by the acquisition 

 of spiracles in conformity with such a transition. 



