MEMOIR OF PALLAS: 95 
sua genera accurate definit, speciesque.* In its com- 
position he availed himself of all that had been 
done before him, including the labours of Marsigli 
and Roemphius, of Peysonelli and Trembley, and 
especially of the more recent discoveries of Linnzus 
and Ellis. Im the volume we find an Elinchus 
Auctorum ad Historiam Zoophytorum Spectantium. 
We thence perceive that he consulted no fewer than 
a hundred treatises on the subject, and in the rich 
collections of Holland he found treasures more 
varied and extensive than probably had ever fallen 
under the examination of any other individual. 
All these he handled as a master. He divided 
those he considered as true zoophytes into 15 genera 
and 250 species; and added three genera which he 
considered doubtful, genera ambigua, comprehending 
22 species. The former included, Ist, the Hydra; 
2, Eschara; 3, Cellularia; 4, Tabularia; 5, Brachi- 
onus; 6, Sertularia; 7, Gorgonie ; 8, Antipathes ; 
9, Isis; 10, Millepora; 11, Madrepora; 12, Tubi- 
pora; 13, Alcyonium; 14, Pennatula; and 15, 
Spongia. The three ambiguous genera are Tenia, 
Volvoces, and Corallina. His definition of sponge 
is animal ambiguum, crescens, torpidissimum ; and 
he distinctly says that corals are to be referred to 
the class of vegetables. But we must not enter 
upon any thing like criticism: Cuvier remarks of 
the work generally, “* that the clearness of his de- 
scription, and the care with which he refers the 
* Bibl. Bot. t. ti. 566. 
