26o 



KINGS LEY. 



EXPLANATION OF THE FIGURES. 



Reference Letters. 



a. 

 an. 

 ar. 

 av. 



bs. 



c. \-c. 9. 



ce. 



ct. 



ec. 



en. 

 ent. 

 es. 

 ev. 



g- 



gl- 



h or ht. 



hep. 

 i. 



iv. 



I. 



lac. 



VI or me. 



mes. 



ml. 

 mg. 

 mo. 

 mt. 



Anus. 



Neural artery. 



Artery. 



Ventral (circumneural) ar- 

 tery. 



Blood sinus. 



Coelomic cavities. 



Cerebrum. 



Cuticula. 



Ectoderm (in figures 50-52 

 edge of carapax). 



Entoderm. 



Entapophysis. 



Entosternite. 



Excretory vescicle of nephri- 

 dium. 



Ganglion. 



Gill-leaves. 



Heart. 



Hepatic duct. 



Intima of heart. 



Invaginations of nuclei in 

 neural anlage {cf. Fig. 29). 



Liver and liver lobes. 



Lacunae. 



Mesoderm. 



Mesenteron and in later 

 stages, intestine. 



Middle line of section. 



Marginal groove. 



Mouth. 



Metastoma, 



mil. 

 71.'— n. 

 11 d. 

 tie. 

 71. a. 



710. 

 7lSt. 



oc. 

 ce. 



cec. 

 on. 



op. 



pd. 



pe. 



pr. 

 ps. 

 pst. 



^g- 

 sn. 

 sp. 

 ss. 



St. 



so. 

 t. 



y- 



ys. 

 yx. 

 I-X. 



54, 

 the 



nephri- 



Muscles. 



Segmental nerves. 



Nephridial duct. 



Nephridium. 



Neural anlage (in Fig. 



the anterior loop of 



nephridium). 

 External opening of 



dium. 

 Nephrostome. 

 Ocellus. 

 CEsophagus. 



QEsophageal commissure. 

 Nerve to ocellus. 

 Operculum. 

 Proctodaeum. 

 Pavement epithelium of cce- 



lom 5. 

 Proventriculus. 

 Pericardial sinus. 

 Primitive streak. 

 Sympathetic ganglion. 

 Sympathetic nerve. 

 Splanchnoplure. 

 Segmental sense (?) organs. 

 Stomodaeum. 

 Somatoplure. 

 Telson. 



Yolk-entoderm. 

 Yolk spherules. 

 Yolk cells. 

 Somites and appendages. 



