184 



J. GRAHAM KERR. 



The true coelom (viscero-pericardial sac, Owen) has received 

 comparatively little attention from previous investigators, 



Fig. 1. 



ini-.. 



haem 



Sagittal section through Nnutilus. 

 Diagrammatic sagittal section through the animal of a young female of Nautilus 

 •pominlins, to show the general relations of the coelom and haemoccel. 

 (The section really passes very slightly to the right of the mesial plane, 

 so as to traverse one of the renal chambers.) 

 haem, hsemocoel; g.c, genital division of the coelom; p.c, pericardial 

 division of the coelom; a, aperture in septum dividing g.c from p.c; k, 

 right inner kidney-chamber; r, pericardial gland corresponding to this 

 kidney-sac; h, ventricle; ov, ovary; ph, crop; giz, position of its opening 

 into the gizzard, which lies to the left of the plane of section; i)it, 

 intestine; v.c, vena cava. 



Grobben and Lankester being the only authors who devote to it 

 more than a few passing words ^ 



It is convenient to treat together the coelom itself, the 



1 Pelseneer, op. cit. p. 192, says that the coelom " s'ltend dorsalement, autour 

 de I'estomac, jusque vers la moitie de I'cesophage. II contient, outre le coeur, 

 la glande gt^nitale, la veine cave et une partie des appendices glandulaires des 

 vaisseaux branchiaux afferents," — a statement which is obviously at variance 

 with the account here given in two important respects. 



