CERATODUS, PROTOPTERUS, AND CHIMARA. 505 
PLATE LXXXIV. 
Fig. 8. Heart of Protopterus annectens, x 4 linear, seen from the front. CA, arterial 
cone; Aw, auriclar appendages ; x, additional lobe of right side of auricle . 
Vn, ventricle ; Per, attachment to pericardium. The right appendage of the 
auricle is thrown back so as to expose the constricted neck of the conus. 
Fig. 9. The same heart, back view. SZ, sinus venosus; vc, ve’, apertures of veins enter- 
Fig. 10. 
Fig. 11. 
Fig. 12. 
Fig. 13. 
Fig. 14. 
Fig. 15. 
VOL, X.—ParT x1. No, 4.—February 1st, 1879. 
ing the sinus; other letters as in fig. 8. 
The same heart, back view, with sinus and auricle opened by a median slit. 
AVY, auriculo-ventricular curtain valve ; FC, basal fibro-cartilage ; Sav, incom- 
plete sinu-auricular valves; other letters as in fig. 9. 
Heart of Protopterus opened from the front by a median vertical cut as indi- 
cated by the dotted line in fig. 8. CA, arterial cone; Aw, auricle; Vn, ven- 
tricle ; FC, basal fibro-cartilage ; vv, rudimentary pocket valves; Sp v, spiral 
valve ; w/v, second long valve of the upper limb of the conus. 
View of the lower border of the arterial cone, showing the pocket valves 
(greatly enlarged). 
Heart of Chimera monstrosa, front view. CA, arterial cone; Vn, ventricle; 
Au, auricle. 
The same heart with the anterior half of the conus and ventricle entirely 
removed. (A, conus arteriosus; B, limit of arterial cone corresponding to 
the lower limit of the upper vertical limb of the Dipnoous arterial cone ; 
AVY, auriculo-ventricular valve; A, fleshy pad; Aw, auricle; Vn, ventricle. 
The same heart seen from behind, with the auricle opened. Sav, sinu-auricular 
valve; Si, sinus venosus; other letters as in fig. 14. 
