PLATE X. 



Structure of the Eye, &c. 



Fig. 1. Single element of the eye of Serolis cornuta, depigmcuted by uitric acid ; 

 li, hyaline cell which has absorbed the pigment. 



Fig. 2. Dissection of Serolis cornuta; h, heart; hej), hepatic CiBca ; ad, oviduct; 

 r, rectum. 



Fig. 3. Diagrammatic transverse section through the eye of Serolis necera; n, nuclei of 

 Semper; I, vitreous body; (g) mass of cells below the vitreous body traversed 

 by a network of pigment. 



Fig. 4. Masticatory stomach of Serolis schythei ; RP, LP, ribbed latertd plates ; /, la, 

 Ip, lateral ossicles ; 1, 2, 3, pyloric ossicles. 



Fig. 5. Diagrammatic transverse section of eye of Scrolls hromleyana ; li, vitreous bodies ; 

 c, cornea ; m, tissue in which vitreous bodies are imbedded. 



Fig. 6. Transverse section through the buccal region of Serolis seiitemcarinata ; a, 

 entrance to the buccal cavity ; m, mandible ; h, buccal cavity ; c, integument 

 bounding the lower surface of the body ; d, salivary glands ; e, connective 

 tissue cells ; n, nerve commissure. 



Fig.^7. Embryo of Serolis antarctica; c, telson. 



Fig. 8. Single element of the eye of Serolis necera isolated by teasing in glycerin ; v, 

 vitreous body with pigment sheath ; g, mass of cells below the vitreous body. 



Fig. 9. Masticatory stomach of /So Wis Z)rom%an«; vu, cardiac ossicle ; F, ventral ossicle ; 

 RP, LP, ribbed lateral plates; /, la, Ip, lateral ossicles; 1, 2, 3, pyloric 

 ossicles ; s, opening of pylorus ; t, triangular ossicle. 



