and Affinities of Oraptolifes. 

 Fisr. 5. i« 



377 



Corbula of A(/ktophenia plmna, 



A. Very j'oung corbula ; B. Oorbula more advanced ; C. Corbula in a still 

 more advanced stage ; D. The matui*e corbula ; E. Transverse section 

 of mature corbula, showing two of its contained gonangia, each with 

 a single gonophore : a, a, leaflets of corbula ; b, b, gonangia ; c, ramu- 

 lus which supports the leaflets ; d, a hydrotlieca. 



F. Separate leaflet from mature corbula : a, continuation of the cavity of 



the supporting ramulus into the leaflet, where it divides into two 

 branches, b,b; c, nematophores, forming tooth-like processes on the 

 distal edge of the leaflet ; d, imperfectly developed tooth-like pro- 

 cesses on the proximal edge ; e, imperfect septum partially dividing 

 the cavity of the leaflet. 



G. Gonangium from mature corbula : a, continuation of somatic cavity 



into gonangium ; b, blastostyle partially suppressed by the enlarging 

 gonophore ; c, gonophore ; d, spadix ; /, ovum ; g, chitinous wall of 

 gonangium. 

 Ann. & Mag. N. Hist. Ser. 4. FoZ. ix. 26 



