12 HiCKSON, Specimen of Osteocella septcntriojialis {Gray). 



was described at length by Kdlliker and is well under- 

 stood. To abandon it now in favour of an older and 

 forgotten generic name will only lead this branch of 

 science into confusion. 



After full consideration of all the characters of the 

 specimen I have come to the conclusion that it cannot 

 justifiably be assigned to any of the well-known genera 

 of Pcnuatulids but represents the type species of a 

 distinct genus. 



Its closest affinities are undoubtedly with the genus 

 Virgularia^ but it differs from Virgularia in the great 

 expanse of fleshy substance on the ventral side of the 

 rachis, in the distribution of the sexual organs throughout 

 the rachis, and in the position of the radial canals on the 

 ventral side. 



It differs from Pavonaria in the absence of spicules 

 in the autozooids and rachis, in the absence of genital 

 organs in the pinn;u and in the presence of radial canals. 



The account given by Kolliker (8) of the structure of 

 \h& x-d.z\\\<, oi Pavonaria finniarcJiica is quite sufficient to 

 prove that this, the type species of Pavonaria, does not 

 belong to the same genus as Osteocella. 



But if it belongs to a distinct genus, to what genus 

 should it be correctly assigned ? 



In a discussion between Stearns and Gray in 1874 on 

 the question of priority, the former asserted that " No 

 description sufficiently accurate to be worthy of con- 

 sideration can be made of the axial rods or bones of this 

 class of animal forms." Notwithstanding this assertion, 

 however, there can be no doubt from an examination of 

 the axis in the British Museum, described by Gray under 

 the name Osteocella septetitrionalis, that it is the axis of a 

 peimatulid belonging to the same genus, and judging from 



