474 



AUGUSTA LAMONT ON 



out, so that, with the aid of the drawings of both dorsal and ventral dissections, a 

 comparison of the several species can be made (Plates I to VIII). 



Thus, throughout the genus, this system of organs consists of five paired groups 



—-c 



N - 



Text-fig. 1. — A group of ampullae from the hyoid capsules, R. radiata. x 5. 

 A. Ampulla. C. Canal. N. Nerve. 



ri 



Text-fig, 

 N. Nerve. 



-Ampullae of R. radiata. 

 A. Ampulla. 



x21. 

 C. Canal. 



of ampullae, situated in the cephalic region, and innervated by branches of the seventh 

 cranial nerves. In many cases each group of ampullae is enclosed in a fibrous covering, 

 the so-called " capsule." The ampullae themselves are irregularly sacculated vesicles, 

 each receiving proximally a nerve-twig, and passing distally into a thin-walled 

 hyaline tube, or canal (text-figs. I and 2), which contains a colourless and trans- 



