The Anatomy of Pentaceros Reticulatus. 



115 



(pol. ves.) is present in each interradius except the madreporic. Two 

 Tiedemann bodies are present in each interradius, including that in which 

 the stone canal is situated. The ampullae (amp.) of the first tube feet 

 arise directly from the ring canal. The radial canal (rad.) runs directly 



Fig. 7. — Diagram transverse section of arm through ampullae and tube feet. 



Fig. 8. — Diagram ambulacra! groove between ampulla and tube feet. 



to the tip of the arm. The tube feet lie in a single row on each side of 

 the ambulacral groove, but the ampullae lie in a double row, an upper 

 and a lower, each tube foot being connected with two ampullae (fig. 7). 



THE ORGANS OF REPRODUCTION. 



The ovaries (fig. 3, ov.) or the testes (fig. 5, ts.) are in the form of 

 bunches or clusters of short, tubular bodies, each cluster having a separate 

 duct to the aboral surface (fig. 5), upon which it opens by a fine pore. 

 In specimens that I have examined I have found from nine to fifteen 

 clusters down the side of each arm. Each cluster having a separate 

 opening, the genital pores form a row along the side of each arm, in 

 position these rows lying one on each side of the interradial septa. The 

 pores may not be made out directly in either the living or the preserved 

 individuals, but their positions may be seen easily during the discharge 

 of the reproductive elements. The ovaries in the fresh material are 

 orange in color, the testes light yellow or almost white. 



