Plaie IV. 



Arabic nuiner.i.Is placed between every two sections indicate the number 



of sections that intervene between those two (exclusive). 



Certain marks on the left of each section are for the identification of the 



sections and do not concern the reader. 



Series I. a-^, — Sections through an embryo of Chelonia cnoiiana, with no mesoblastic 

 somites ; taken out 9^ days after deposition. Surface views given in 

 Figs. 1 and la, PI. I. For detailed description, see p. 33. CCx2. 



(B lib) 



Series 11. ä-h. — Sections througli an embryo of Trionyx japonicus with 2-3 meso- 

 blastic somites, taken out 4 days after deposition. Surface view given in 

 Fig. 18, PI, III. For detailed description, see p. 36. Cc'x 2. (136 ß) 



Series III. a-m. — Sections through an embryo of Clemmys jajwnlca with 5 mesoblastic 

 somites, taken out 4^ days after deposition. Surface view given in Fig. 

 10, PI. II., {^CoHtrib. II, PI. I, Figs. 2 and 2a). For detailed description 

 seep. 39. CCx2. (XXXXIX) 



Series IV. a-/, — Sections through an embryo of Trionyx jajwnicus with 4 mesoblastic 

 somites, taken out 5Ä days after deposition. Surface view in Fig. 19, 

 PI. III. (and also in Contrih. II, PI. III., Figs. 17 and 17</.) For detailed 

 description see p. 42. CCx2. (I28a) 



