PEOCEEDINGS OP UNITED STATES NATIONAL MUSEUM. [1885. 



EXPLANATIOIT OP PLATE VIH. 



Kefbbhnces: ab, air-ljladder ,- ao, aorta; aw, auricle; 6a, 'bulbns aortas; ch, chorda dorsalls; ep, 

 epiblast of yelk-sao; fm, foUicnlar membrane; fv, follicnlar ressel; i, Intestine; L, 

 liver ; mp, follicular pore ; ms, medulla spinalis ; pf, muscular mass at base of pectoral ; 

 sv, sinus venous ; t, pectoral in section ; vc, vonas caudalis andcardinales ; ve, ventricle; Wd 

 Wolffian duct ; y, yelk ; yhy, yelk hypoblast or periblast. 



Fig. 8.— Transverse section tbrougli the heart, showing its chambers, x 35. 



Fig 9. — Transverse section through a follicle containing an embryo, cutting through the plane of the 

 follicular pore, x 32. 



Fig. 10.— a follicle containing an embryo with two immature eggs attached near the foUicularpore. 

 xl5. 



Fig. 11. — Ovary of Oambusia, showing the way in which the ripe ova are attached to the median ves- 

 sel. X 3. 



Pig. 12. — Follicular pore and adjacent parts of memhrane of a follicle, showing the course of the ves- 

 sels, from a transparent preparation in balsam, x 65. 



