Piate 2. 



Anelasma and Sacculina. 



b.c brood cavity. eh chitin. ch.pd chitin of peduncle. ch.pl chitinous plug of vas deferens. 

 cn connective tissue sheath of testes. d hypertrophied germinai cells. d % Later stages in degeneration 

 of d. ec ectoderm. ep epithelium. gm germinai epithelium. I lumen of testis. lag lagena, lac lacunar 

 tissue. muse muscle. ov ovary. ov.deg degenerate ova. pigm pigment. r root. s spermatozoa. sp sper- 

 matocytes. t testis. vd vas deferens. vd.op opening of vas deferens. q^ complemental males. 



Fig. 1. Section through a piece of ovary of Inachus scorpio, into which a root of Sacculina has penetrated. 



The root exhibits a lagena [lag) at its extremity. Degenerating ova [ov) are seen in the ovary. 



X 650. 

 Fig. 2. Optical section of a root-branch of Sacculina. X 50. 

 Fig. 3. Optical section of roots of Anelasma squalicola. The roots are shown springing from the surface of 



the peduncle [ch.pd), the chitin of the latter being pushed out to form the chitinous investment 



of the roots [eh). X 50. 

 Fig. 4. Part of a section through the peduncle of Anelasma squalicola, from the surface of which a root is 



seen to spring [r). In the interior of the peduncle the ovary is shown [ov), at the borders of 



which ova [ov.deg) are beginning to migrate into the lacunar tissue [lac). X 40. 

 Fig. 5. Section through a piece of the mantle of Anelasma squalicola showing the migrated ova [ov.deg) in 



process of degeneration. X 80. 

 Fig. 6. Transverse section through anterior region of testis of young Sacculina neglecta. X 865. 

 Fig. 7. Longitudinal section through the middle region of the testis of Peltogaster curvatus. X 435. 

 Fig. 7a. Spermatozoa of Peltogaster curvatus. X 865. 



Fig. 8. Transverse section through posterior region of testis of young Sacculina neglecta. X 865. 

 Fig. 9. Transverse section through middle region of testis of Peltogaster curvatus. X 435. 

 Fig. 10. Transverse section through posterior region of testis of older Sacculina neglecta. X 865. 

 Fig. 11. Longitudinal section through the middle region of the testis of an olà Peltogaster curvatus. X 435. 

 Fig. 1 la. Longitudinal section through wall of testis of old Peltogaster curvatus. X 435. 

 Fig. 12. Transverse section through posterior region of testis of an adolescent Sacculina neglecta. X 435. 

 Fig. 13. Section through the vas deferens of Parthenopea subterranea. X 234. 

 Fig. 14. Transverse section through young Sacculina neglecta externa with complemental males (q 1 ). X 93. 



