CRUSTACEANS. 246 



eeptacle rather seems to be the empty valve of one of the species. Fig. 25. 

 Of tlmv Midi valves, one contained eighteen ova, another twenty, the 

 third twenty-four. Probably, these were produced by three different 

 animals. 



Spawn had appeared on September 15, and on October 5, some of 

 the young were hatched. They were very minute. The microscope 

 detected nothing. 



PLATE LX 1 1 



Fio. 19. Cyprit pilota t 



20. Tho same, enlarged. 



21. Empty nhelln more enlarged. 



22. Empty specimen. 



23. Exuvia. 



24. Ova, enlarged. 



25. Ova deposited in the empty valve of a shell. 



Considerable variety of the tribe Entoinostraca may be found in 

 Scotland, such as the Ci/pris lavis, which dwells along with the preced- 

 ing, and is of smaller size. A specimen spawned in autumn. 



PLATE LXX. 



Fio. 10. Cyprit knit. 



1 1 . Spawn magnified. 



CTPWS FOBTHENSIS. Plate LXX. 



A very minute species of the Cypris inhabits the estuary of the 

 Forth, which I have obtained several times. Plate LXX. figs. 12, 13, 

 14, 15. This is of a very faint, dull, reddish-brown, the shells opaque, 

 somewhat resembling those of a mussel, and several exposing one or 

 more black internal specks. The animal springs through the water, and 

 crowds of it congregate on the sides of the vessel towards the light. 



PLATE LXX. 



Fio. 12. Cyprit Fortiauit, group. 



13. Another group. 



14. Group enlarged, the shells closed. 



15. Specimen protruding parts of the animal, enlarged. 



