1007.] NATURAL SCIENCES OF PHILADELPHIA. 399 



iuuuetliutely bchiml it.s po.'ilero-latt'ral corner. Tlie iiitL'stiual lobe 

 (RK) is somewhat strap-shaped and extends well forward toward the 

 head. In color the ri^lit kidney is of a grayii^h brown tint, varying to 

 M buff shade, llistolouically the tissue consists of minute pouches, or 

 acini, which open into small channels, these into larger ones, and so on 

 to the main ducts. The cells are of the usual cul)ical form, and are 

 crowded with ))igmented waste products of granular appca.ance. 1 

 have seen nolhing in my material that seems to warrant any further 

 discussion of the tissue, which has been well described by others. 



The reproductive si/stc7n in Ilaliotis is interesting, among other things, 

 because of the lateness of its development, and the rapidity of the same 

 when once beguiL Careful microscopical examination of small specimens 

 reveals at best only the slightest development or not even a trace of a 

 germinal epithelium. Even in specimens 3 cm. long the latter is 

 demonstrated with difhculty. In average-sized individuals, and 

 larger, the gonad is well developed, especially at the height of the 

 breeding season, which occurs earlj^ in the rear. The testis is of a 

 cream color, the ovary a slaty green. There is practically no difference 

 in size between the glands of the two sexes, very nearly the entire sur- 

 face of the main visceral mass being covered 1)>' the organ. 



In small specimens of H. cracherodii, of about 2 cul in length, the 

 whole of the visceral mass to the right of the pericardium, except one 

 small area (a portion of the stomach), is of a brownish color. This is 

 due to the extensive liver, which forms the horn-shaped portion of the 

 visceral mass, extending along the right posterior curve of the colu- 

 mellar muscle. At the left of the caecum the stomach is in contact 

 with the body wall, and projecting through the li\-er forms the i regular 

 whitish area noted above. Examined externalh' specimens fully 5 

 cuL in length show no clianges from the condition just described. 

 From this time forward, however, the development of sexual products 

 commences to manifest itself. The first outward indication is a gray- 

 ish tinge at the tip of the horn (of the visceral mass), which gradually 

 extends itself over the remainder of the liver. Individuals 6, or at 

 most 7. cm. in length possess a grayish coating entirely investing the 

 horn. This thickens, and in specimens S cm. long there is a well estab- 

 lished gonad extending to some extent over the main visceral mass. 

 As may be supposed, the thickest part is at the tip of the horn, where it 

 measures about 3 mm. in depth. The males and females of this size 

 exhibit practically no difference in gonad coloration. 



Sections through the gonad of males and females ])etween 7 and 8 

 cm. long revealed sperms or ova that while innnature are in well 



