110 SUPPLEMENT. 



as new species may exist on the opposite mainland, for very little is known of the 

 vegetation of Yucatan. Taking present data, however, the Flora of Cozumel is probably 

 more West-Indian than continental American in character ; for, although the number 

 of species, excluding doubtful ones, common to Cozumel and the continent but not 

 found in the West Indies is somewhat larger than the number of West-Indian species 

 found in Cozumel but not on the mainland, those of the latter category are of a more 

 distinct type than those of the former. Thus Mhachicallis and Ernodea are very distinct 

 monotypic genera — the former ranging from the Bermudas and Bahamas to Cuba and 

 Jamaica, and the latter from Southern Florida and the Bahamas to Guadaloupe and 

 Jamaica. Bhus metopium, which with one other Cuban species Engler has recently 

 raised to the rank of an independent genus, is only West-Indian and Floridan ; Trichilia 

 terminalis, is a common tree in Jamaica, not recorded from elsewhere ; and Ambrosia 

 hispida and Euphorbia trichotoma are decidedly well-marked species restricted to the 

 Floridan and West-Indian region ; while the remainder are doubtful or less distinct. 

 It is true that the majority of the plants named are essentially littoral. On the other 

 hand, there is not one continental genus represented in the flora of Cozumel, so far as 

 is known, which is not likewise West-Indian. Sambucus at first seemed to be a note- 

 worthy exception, as the genus does not appear in Grisebach's ' Flora of the British 

 West Indian Islands,' nor, apparently, in any other record ; but on looking through the 

 Kew Herbarium a specimen of a species of Sambucus was found labelled " St. Vincent, 

 Rev. L. Guilding." It may or may. not be the same species as that from Cozumel, and 

 there is a possibility of a mistake, as there is no original label. The New World range 

 of Sambucus is from Canada to North Florida and California, through Mexico and the 

 Andes to Chili, South Brazil, and Buenos Ayres. 



In composition Mr. Gaumer's collection of Cozumel plants offers almost a parallel to 

 Professor Moseley's collection from Fernando Noronha*, probably owing to similar 

 causes. Gaumer found only one species of fern — a form of the almost ubiquitous Pteris 

 aquilina — Moseley none ; Gaumer two or three petaliferous monocotyledons and five 

 grasses and sedges — Moseley no petaliferous monocotyledons, but two or three more 

 grasses. As in most insular floras, the proportion of genera to species is high in 

 Cozumel: thus the 141 species belong to 121 genera and fifty-four natural orders. The 

 only genera represented by more than two species are : Ipomcea, Solanum, and 

 Euphorbia. Among the plants described as new, Bravaisia tubiflora is perhaps the 

 most interesting, as it is the second species of the genus, the other ranging from Mexico 

 to Peru and also occurring in Trinidad ; and the new species is the same as a specimen 

 collected by Hahn at " Tlacatalpan," probably Tlacotalpan, near the coast, in Vera 

 Cruz. 



* See Hemsl. Bot. Chall. Exped. i. 2, p. 9. 



