MR, C. TATE REGAN ON THE 



connection with the priapium, whilst the priapiiun itself has a 

 special skeleton. 



Cleithra. — The cleithrum of the proctal side is normal and ends 

 anteriorly below the angle of the prseopei'culnm. That of the 

 aproctal side is produced into a slender process (cl.) that extends 

 forward to below the attachment of the urohyal ; this process lies 

 between the isthmus and the priapium ; it is somewhat expanded 

 transversely (PL I. A), and anteriorly it sjareads downwards on 

 each side of the priapium, almost enclosing it. 



Text-fiofure 3. 



Neostetlius lanJcesten 



Skeleton of priapium from the aproctal side (X 12) 

 (diagrammatic). 



eta 



. ctenactiniiun ; u., uroliyal ; cL, cleithrum ; tr., tr.', transverse processes of 

 third vertebra; c, cartilage; 7:, r'., first pair of ribs; ac, antepleural carti- 

 lage; pva., pulvinular appendage; jjvs., pulvinular spine; pv., outer, and 

 pv.' , inner pulvinular bones ; is., anterior, and is.', posterior infrasulcav bones ; 

 p., papillary bone ; a.r., vertical, and a.r.', horizontal anterior ridges of axial 

 bone : Ir,, its lateral ridge ; or., its main crest ; and st., its terminal style. 



Third vertebra. — The transverse process of the aproctal side {tr' .) 

 is normal, but that of the proctal side {tr.) is much stronger; 

 pi oximally it is directed outwards at right angles to the centrum, 

 then it i-uns forwards below the transverse process of the second 

 vertebra (text-fig. 4B), until it reaches the level of the first 

 vertebra, when it curves downwards and ends. 



First pair of ribs. — These are attached proximally to the 

 transverse processes of the third vertebra ; the rib of the aproctal 

 side (r.') is not particularly strong, but it is ver}^ long and runs 

 downwards and forwards into the priapium ; the rib of the 

 proctal side (r.) is much stouter and runs downwards right to 

 the ventral surface of the priapium below the anus (text- 

 fig. 2, r.); proximally a nodule of cartilnge (c.) intervenes 



