107 



Fig. 37. Lamina of (^ill oi" T. navalis, to show especial- 

 ly the distribution or tb.e glands of Doshayos , in which the 

 elements are represented semi-diap;rami!iatically. The arrows 

 indicate the course of the water anrl lilood ciirronts over the 

 lamina. The epibranchial cavity and the blood vessels are 

 indicated by the letters v/hich are jilaced in tJiese spaces. 

 X 312. 



Fig. 38. Transverse section of three laminae almost in 

 the line of the louver arrow in fig. 32. Tvra interlaminar 

 junctions are shown. The two elements of the gland of De- 

 shayes arc shown, both as to character and distribution. 

 X 312. 



Fig. 39. Tangential section of a gill to sh.ov/ the dis- 

 tribution of the inter-laminar junctions, x 312. 



Fig. 40. Transverse section of three gill laminae, along 

 the line shov/n in fig. 37, near the tip of the lamina, so as 

 to sho\r the interlaminar junctions on one side, x GGO. 



Fig. 41. Section of the three most anterior gill fila- 

 ments at the side of the "hood". The one to the left is only 

 a half filament. The letters are placed in the epibranchial 

 canal, x 860. 



Fig. ; • . Group of cells from, the branchial groove at the 

 edge of t?ie gill, showing the character of the ciliated r-nlls 



