168 THE CCELOM AND NEPHKIDIA OF PALJiMON SEERATUS. 



DESCRIPTION OF PLATES XIII, XIV, and XV, 



Illustrating Mr. Weldon's paper on the " Coelom and Nephridia of 



Palsemon serratus." 



Reference Letters, 



a. op. Ophthalmic artery. B. Bladder. B. ep. Bladder epithelium, b. v. Blood- 

 vessel. CcB. Coelom. e. s. Eud-sac. Ql. Eud-sac. Ov. Ovary, u. Ureter. 



Fi0. 1. — The coelom and right nephridium of Palcemon serratus, dissected out. 



Fig. 2, a, b, c. — Eight diagrams of sections through the hladder, showing the existence 

 of more than one communication with the nephridial tubules. 



Fig. 3.— Epithelium of bladder. 



Fig. 4. — Epithelium of a renal tubule near its entrance into the bladder. 



Fig. 5. — Epithelium of a renal tubule in the middle of its course. 



Fig. 6. — Diagram of the arrangement of the bladder, tubules, and end-sac. 



Fig. 7. — Section through the end-sac. 



Fig. 8. — Section showing the communication between the bladder and the coelom. 



Note. — The shading in Figs. 2 and 8 is obviously diagrammatic ; but the outlines are in 

 both cases determined by means of a Camera Lucida. 



