The pronephros of Chrysemys uiargiuata. 31 



5,42—5.49 XVIII 5,40-5,47 



5,50—6,3 XIX 5,48- 6 J 



6,4 —6,12 XX 6.2 —6,10 



Pronephric duct ends 6,42 Pronepliric duct ends 6,37 



The neurenteric canal begins at 6,48. 



Pronephros on the left side. 



Vascular glomus begins at 3,9 — 



3 22 I 



o oo \ Nephrostome opening into coelom. 



o.Zo J 



3.26 ( The pronephric duct is solid in this region and 



3.27 J apparently degenerating. 



3.28 \ 



VII 



VIII 



o„Q / Small nephrostome opening to coelom. 



3,36 — 3,38 Tubule opens into coelom direct and into duct 

 in 3,40. 



( I Tubule distinctly arising from the open nephrotome 



IX 3,43 and opening into the duct at 3,49: there is appa- 



I rently a solid connection with the coelom at 3, 48. 



j Tubule with nephrotomic opening at 4,3, and also at 4,6. 



^ 1 4,7 and 4,8. 



Pronephros on the right side. 



Glomus begins 3,11 — 



( 3,16 — 3,18 Nephrostome and tubule 



3,22 , 



o'or, ( Tubule opens to coelom direct and into duct at 3,31. 



] Qoo f Another coelomic opening 



VIII 



3,33 A tubule passes off from the open nephrotome: it has 



a separate opening into coelom at 3,36, and opens into 



pronephric duct at 3,38. 



[ 3,45—3,47 A tubule passes off from open nephrotome: it 



IX has a solid connection with coelom or lower end of 



I nephrotome at 3,49 and 3,50. 



[ There may be a continuous connection between duct and 

 X I nephrotome in this region: there are distinct traces 



of a connection in 4,6 and 4,7. 



