172 Miscellaneous. 



without any bony plates. The single specimen obtained had the 

 peculiarity (most probably individual) that the lower canine tooth 

 on one side, like a true Alligator's, fitted into a notch, and on the 

 other side fitted into a concavity in the upper jaw as in the croco- 

 diles. In most other characters, and especially in the belly being 

 protected by bony plates, it agrees with the alligators of Brazil. 

 Other specimens of this alligator are very desirable, to confirm the 

 characters assigned to it. — J. E. Gray. 



On the Habits of Hyalonema. 



Dr. Gregory writes, " My friend Mr. Cramer, who is collecting 

 plants for Mr. Veitch, has been down three or four times to fishing- 

 villages at Inosima to look after the Hyalonema, and the whole of 

 his researches point to this : — ' The Japanese do not know where to 

 find it, but occasionally it comes up in their nets, in deep water : 

 they say it has the same appearance as when dried, and that it has 

 no slime or gelatinous substance adhering to it.' " 



Note on the Vitality of a Sponge of the Family Corticatse (Tethya 

 lyncurium, Lamarck), By M. LfoN Vaillant. 



The author has endeavoured to investigate the mode in which the 

 Sponges repair accidental loss of substance, and to graft them upon 

 each other in various ways. He employed principally Tethya lyn- 

 curium, Lamk., belonging to the section Corticatse, 0. Schmidt, which 

 is common on the shores of Brittany, and the regular form and histo- 

 logical complication of which render it better fitted for experiment 

 than the Halichondriae. 



Of these Sponges the author endeavoured to isolate the cortical 

 and afterwards the medullary substances ; he cut away portions 

 taken in different directions, to observe the mode in which the re- 

 production of these tissues is effected, and their cicatrizations ; and 

 he attempted to graft Tethya lyncurium upon itself, and also various 

 Sponges of the genera Lycon, Halichonclria, Reniera, and Polymastia 

 upon that species. From more than fifty experiments he draws the 

 following conclusions : — 



1. The two substances of which Tethya lyncurium is composed 

 are mutually capable of reproduction, the isolated medullary sub- 

 stance reproducing the cortical substance, and vice versa. 



2. The vitality of the cortical substance is greater than that of 

 the medullary — which is in relation to its histological constitution. 

 It is able to produce prolongations capable of reproducing adherence. 

 Its contractility is also more noticeable than that of the medullary 

 substance, if, indeed, the latter possesses that property. 



3. The cortical substance certainly plays a special protective part 

 in the economy of the Sponge. 



4. The grafting of individuals in this species is easy, but it requires 

 a certain time for its completion. 



5. The grafting of a different genus upon Tethya lyncurium has 

 not hitherto succeeded. — Comptes Renclus, Jan. 11, 1869, tome lxviii. 

 pp. 86-88. 



