VOL. L.] PHILOSOPHICAL TRANSACTIONS. 3 I 1 



been taken for fruit or berries by sontie gentlemen, who consider the internal or horny part of the 

 sea-fans as vegetables. 



Fig. 20, is a very curious barnacle, taken from an elegant specimen in the British Museum j which 

 from its figure Mr. E. called the Persian crown. 



As to the nature of these animals: on opening the shells of many of the com- 

 mon English barnacles (fig. 1 ) while they were alive, Mr. E. found the lower 

 part of the shell, which contained a cavity equal to two-thirds of the whole, full 

 of spawn; so that the barnacles, which adhere by the base of their shells, as 

 well as those that are supported by fleshy tubes, are propagated by eggs, which 

 they send forth in inconceivable numbers ; as appears by the clusters of young 

 shells, which we find adhering not only to the parent animals, but to all hard 

 substances near them. The bottom shell of these animals, as well as their upper 

 shells, vary in form according to their situation, which occasions some difficulty 

 in determining their several species with exactness. The form of the base shell 

 of our common English barnacle, is the flat radiated figure represented adhering 

 to a scallop shell in the front of a group of them at fig. ]7. The barnacles at 

 fig. 8, 9 ; 14, 15; and 20, have the same kind of base. 



Mr. E. observed a singular kind of flat balanus, on a white mandrepora coral 

 from the coast of Italy, in the possession of Mr. Mendez D'Acosta, f. r. s. 

 whose base appears sunk into the coral, and of the form of an inverted cone, 

 bending a little to one side. The inward surface of this conical base shell ap- 

 pears curiously striated with tubular radii, which terminate on the surface of the 

 coral, to receive the extremities of the 6 valves, that compose the upper shell. 

 This peculiar form of the base seems owing to the animals of the coral and of the 

 barnacle growing up together, the latter keeping possession of its proper space, 

 while the former grew" close about it. 



The bottom shell of the barnacle like a limpet, at fig. 18, increases from a 

 small point by many thin shelly margins, which exactly correspond to the inden- 

 tations which we observe on the base of the outer shell ; so that it appears not 

 unlike the drawing of a fortification in miniature. The Rev. Mr. Borlase is 

 now of opinion, that the Cornish barnacle at fig. 1 6, which he has described in 

 his History of Cornwall, is rather a limpet or patella. 



CXIF. A Further Account of the Poisonous Effects of the Oenanthe Aquatica 

 Succo viroso crocante of Lobel, or Hemlock Dropwort, By W, Watson^ 

 M. D., F. R. S. p. 856. 



In June 1746, Dr. W. communicated to the r. s. some observations concern- 

 ing the oenanthe aquatica succo viroso crocante of Lobel,* in respect to its 



♦ Oenanthe crocata, Linn. 



