37 6 SCIENCE PROGRESS. 



as common at St. Paul in Bourbon. It inhabits Eastern 

 tropical and South Africa, though it is not known 

 from Madagascar or any other of the African islands. Six 

 or seven species of Hydnora have been described ; all in- 

 habiting Africa from Abyssinia and Angola southward to 

 Cape Colony. I have previously noted (62) the discovery of 

 a member of this order (Cytinus Baroni) in Madagascar. 

 Since writing that I have seen a third Mexican species. 



The intimate relationships of the floras of Bourbon and 

 Mauritius may be gathered from the presence in the two 

 islands, and restriction to these islands, of the following 

 monotypic, mostly very distinct, genera: Cossignya and Dora- 

 toxylon (Sapindacese), Grangeria (Rosaceae), Roussea (Saxi- 

 fragaceae), Psiloxylon (Lythracese ?), Fernelia (Rubiacese), 

 Heterochcenia (Catnpanulacese), Bryodes (Scrophularineae), 

 Monimia (Monimiaceae) Dictyosperma (Palmae). To these 

 may be added several other genera of the same geographical 

 area, represented by more than one species ; in five instances 

 out of six by three species : Fostidia (Myrtaceae), Pyrostria 

 and A/y 07itma (Rub'iacedz), Faujasia (Composite), Hyophorbe 

 and Acanthophcehix (Palmae). Twenty-five other character- 

 istic genera are restricted to the African region, using that 

 designation in the sense of including therein the islands 

 under consideration, Madagascar, and continental Africa. 

 Trochetia (Sterculiaceae) is remarkable among them as 

 extending to St. Helena, where it is represented by two 

 distinct species — or rather was, for one is quite extinct in 

 a wild state. Psiadia (Composite) has the same range. 



Allusion has been made (63) to the phenomenal con- 

 centration of endemic palms in the Seychelles, and it would 

 be interesting to give the distribution and affinities of the 

 palms of the whole of the East African Islands ; but I must- 

 confine myself to the Bourbon species. The native species 

 are five in number, namely : Latania Commersonii, Hyophorbe 

 indica, Dictyosperma album, Acanthophcenix rubra and A. 

 crinita. All these palms also inhabit Mauritius, and 

 they are, so far as our present knowledge goes, confined to 

 the island. All the genera are peculiar to this insular region 

 if we take in Madagascar, and Dictyosperma and Acan- 



