Miscellaneous. 397 



passages as will make it clear that he deserves the credit which has 

 been assumed by those who have merely repeated his observations. 

 On page 430, ' Comptes Rcndus,' he says, " Ainsi le spicule ou dard, 

 figure dans I'interieur du sac par M. Corda (calcarea saffitta, Corda), 

 et reprcscntc saillant au dehors par M. Ehrenberg, dans sa planche 2. 

 fig. 7 b, n'est autre que I'espece de calice basilaire a trois points eu 

 etoile, des pretendus hame9ons. Le long filament grele qui part de 

 ce calice etoile etait, avant revolution, invaginc en dedans de lui- 

 meme et du calice ou spicule par un retournement en doigt de gant, 

 et formait au fond du sac cette apparence de coussin que M. Corda 

 a nomme vesica jtatelliformis ; uu examen attentif et d'excellents 

 instruments font meme reconnaitre dans ce coussin sa composition 

 par un fil enroule' en spirale." On page 431 he speaks of the evolu- 

 tion of the thread of this and another smaller nettling-cell by en- 

 sheathing itself: "des corpuscules plus petits et surtout bcaucoup 

 1)lu3 etroits que les precedents, ovoifdes, i parois cpaisses contenant a 

 eur intcrieur un fil enroule en spirale, qui sort comme le long fila- 

 ment des hame9ons, en s'engaiiiant en dedans de lui-mcme." All that 

 I have been able to add to this, although the subject has been pur- 

 sued with the utmost rigour, and with the best lenses to be had, is 

 the description of the relation of the coiled thread to that part of 

 its base which projects straight into the cavity of the cell. Perhaps 

 the greatest importance that can be attached to this is that it is the 

 most difficult to make out. However, the discovery of this feature 

 solves the whole mechanism of the organ. Although 1 had, in I8G0, 

 figured and briefly indicated ( Agassiz's ' Contributions ' ut suprh) 

 this part of its structure, yet it was not until the fourth volume of 

 the 'Contributions' appeared, in 1862, that I described it, in full, as 

 I had seen it in various animals, viz. in the ephyra of Aurelia flavi- 

 dula (p. 44), the Hydra form of Coryne mirabilis (p. 209), Actinia 

 tnarginata (p, 210), and Uydractinia jmlyclina (p. 23"). At first 

 sight, I migiit seem to be anticipated in this by Gosse, in his * Even- 

 ings with the Microscope,' London, 1859, or in his 'Actinologia 

 Britannica,' London, 18(50, p. xxix. Introduction, and pi. II. fig. 6; 

 but, upon examination of the illustration, I find nothing to justify it; 

 and, from the description in connexion with the figure, I should 

 judge that the cnidae had been injured and distorted by pressure. 

 However, I leave it to others to decide whether Gosse' s description 

 is sufficient to clear up the subject on this point. 



Among the Ctenophort^ the cnidce are so numerous and so closely 

 packed together, as to form a uniform layer all over the surface of 

 the tentacle totally outside of the exterior wall. — H. J. C] 



On the Writings o/C. S. Rafinesque. 



To the Editors of the Anmis a)id Magazine of Natural History. 



Gentlemen,— Will you allow me to state, for the information ot 

 your readers, that a long-desired work is about to be accomplished 

 in Philadelphia, iiamelv, the reproduction of the complete writings 

 of Constantino Sinaltz 'llafinesque on Recent and Fossil Conchology, 

 to be edited by W. G. Binney and G. W. Tryon, Juu. This indus- 



