1(34 BALA MILE. 



brook, so as to be covered by pure water during the ebb 

 of eacli tide. Sessile cirripedes adhere to all sorts of 

 objects, floating and fixed, animal and vegetable, living and 

 dead, organic and inorganic. Chthamalus is, perhaps, more 

 commonly attached to rocks than are the other genera. 

 Living Mollusca are, I think, the most frequent objects of 

 attachment : Mr. Cuming has remarked to me, that shells 

 covered by an epidermis, as Patella, Haliotis, and Mytilus, 

 are the greatest favorites. Acasta is always imbedded in 

 sponges, or in the sponge-like bark of I sis ; Pyrgoma and 

 Creusia in corals ; Chelonobia is attached to turtles, and one 

 species to crabs or very smooth shells ; Coronula, Tubici- 

 nella, and Xenobalanus, are imbedded in the skin of 

 Cetaceans ; and Platylepas in that of manatee, turtles, or 

 sea-snakes. 



If we attempt, with our present not very imperfect 

 materials, to divide the globe into provinces, according to 

 the amount of difference in their Cirripedial inhabitants, 

 including all orders and families, and disregarding entirely, 

 as I think we ought, all probabilities or conclusions deduced 

 from the distribution of other tribes of animals, we find 

 that the globe may be divided into the four following great 

 provinces and one sub-province. I should premise, that in 

 the following remarks and tables," the species of Lepas, 

 Conchoderma, Chelonobia, Coronula, Platylepas, and Tubi- 

 cinella, are excluded, owing to their being attached to float- 

 ing or swimming objects, and being consequently widely 

 and irregularly distributed. 



The first, or North Atlantic province, is that of Europe 

 and the eastern shores of North America, from the arctic 

 regions to lat, 30° : the island of Madeira, part of the 

 north-west coast of Africa, and the whole Mediterranean 

 being included. In this province (the above-named genera 

 being excluded) we have 31 species, of which 22 are not 

 found in any other distant quarter of the globe. As some 

 few of these species range into the West Indies, I have not, 

 on this account, excluded them from the 22 peculiar forms. 



* As the number of Cirripedes in the whole class is not very great, I have 

 given lists of the species in the four main provinces and in the one sub-province. 



