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EXPLANATION OF PLATE X. 



Fig. I. Sapphirina Edtvardsii, Haeckel, viewed from the ventral 

 surface, and showing the course of the alimentary canal, the dis- 

 position of the dermal glands, fat spheres, eyes, and ramifications 

 of the nervous system. (Note : The muscles, genital organs and 

 swimming feet, etc., are omitted.) 



Fig. II. Anterior portion of cephalic region of same species, showing 

 in greater detail the arrangement of the eyes, fat-body, dermal 

 glands and nerve connections. 



Fig. III. - Posterior "maxilliped" (really a branch of the second 

 maxilla) ; same species. 



Fig. IV. Caudal plate ; same species. 



Fig. v. Combination of a single-celled dermal gland and a terminal 

 ganglion cell with its sensory bristle ; same species. 



Fig. VI. Sapphirina Gegenbauri, Haeckel, ventral view to show the 

 eyes, alimentary canal, liver lobes and reproductive system. 

 (Nerves, muscles and most appendages are omitted.) 



Fig. VII. Posterior "maxilliped" (branch of the second maxilla); 

 same species. 



Fig. VIII. Caudal plate ; same species. 



Fig. IX. Caudal plate of S. Clausi, Haeckel. 



Fig. X. A swimming foot of S. Clausi from the fourth segment, 

 showing the two nearly equal branches. 



Fig. XI. A similar foot from S. Darwinii, Haeckel, showing how the 

 inner branch is here almost suppressed. 



Fig. XII. The medium eye-spot in S. Darwinii, greatly magnified. 



LETTERING. a. anterior antenna; c. corneal lens; d. chitinous cuticle ; 

 /. fat sphere, secreted by the " Fat-body " ; g. central ganglionic 

 mass penetrated by the oesophagus (oe) ; h. branch of that peculiar 

 form of connective tissue know as the " Fat-body " ; i. intestine ; 

 k. stellate branches of the " Fat-body"; I. liver lobes lying 

 around the stomach; Is. crystalline cone ; m. muscles; me. median 

 unpaired eye; n. nerve; o. anus; ce. oesophagus ; p. pigment body 

 of the paired eyes; pa. posterior antenna; pg. peripheral ganglion 

 cell with its sensory bristle ; r. spermatophore pouch ; s. vas 

 deferens ; st. stomach ; t. testis ; y. dermal gland ; yg. double-cell 

 consisting of a dermal gland and a ganglion cell ; x. problematical 

 organ (sensory?). 



(All figures after Haeckel.) 



