10 HIRUDO. 



appearance is limited to no particular season. The latter were larger 

 than the others, being about the sixteenth of an inch in diameter. 

 Though preserved a long time, they did not undergo any change ; and 

 as nothing tended to elucidate their nature, I ceased to consider them as 

 connected with the propagation of the leech. Some are represented 

 Plate I. figs. 17, 18, 19, natural size ; and fig. 20, enlarged. 



Some capsules, of an oval form, have been seen in vessels containing 

 similar leeches. 



Nothing of a particular interest has been disclosed by these animals ; 

 some are in more active motion than above described, though still ad- 

 hering by the sucker, which has appeared very thin and transparent. 

 In certain positions, the microscope discovers that the body consists of 

 numerous annulations. 



Some specimens being replete with blood on coming from the sea, 

 the sustenance of those animals may be considered as probably derived 

 from sources similar to that of the Hirndo muricata. 



Their faculties are certainly very obtuse ; or a particular state is 

 attended with particular incapacity. If left dry above the surface of the 

 Avater, they do not descend in quest of it, but remain on the spot to 

 perish. 



Fig. 2 represents a group of smaller leeches, which may be the same 

 as the preceding in earlier stages ; but their features were not equally 

 definite, farther than in the appearance of the sucker. 



An animal somewhat of the same character is represented in the 

 Dictionnaire d'Histoire Naturelle. I can scarcely presume to identify 

 mine with that represented by Chamisso and Eysenhardt in the Nova 

 Acta Physico-Medica, Academics Leopoldino Carolina; Naturce Curiosoriini, 

 torn. x. p. 350. ; torn. xxiv. fig. 4, Brusige, 1821. 



PLATE I. 



FIG 16. Hirudo vittata. 



17. 18, 19. Supposed capsules, natural size. 



20. Three capsules, enlarged. 



21 . Group of leeches, supposed the same as fig. 1 6. 



