Zooloyical Society. 385 



the filaments in question that we see the spores which are produced 

 at the tip of the same cell which produces the filaments. These in 

 Chordaria flagelliformis, which has served as the type for the descrip- 

 tion of the genus, are elliptic, resembling in form that of melon- seeds. 

 The border of the spores is transparent and of a greater or less breadth. 

 We have never met with ' propagules.' 



" We see then, by an approximation of the principal characters 

 drawn from the two precechng descriptions, that the essential differ- 

 ence between Chordaria andMesogliea resides less in the cartilaginous 

 consistence of the frond than in the intimate structure of the axis, 

 which might be called cellular in the first and filamentous in the 

 second. Nevertheless, this consistence, which depends on the closer 

 texture of the centre of the frond, is more constant in Chordaria, and 

 may be given as a secondary character. In Mesoglasa w^e know in 

 fact the Brazilian species only which presents this cartilaginous con- 

 sistence, which ceases when the radiating filaments have partly fallen, 

 that the remainder of the frond, far from collapsing, preserves the 

 cylindrical form proper to Chordaria, whence the name of M. chor- 

 darioides is well adapted to it*." 



This is a specimen of the manner in which the author illustrates 

 his subject, almost every species affording an opportunity for some- 

 thing interesting, of greater or less length. We must content our- 

 selves with the above rather copious extract, only indicating those 

 species and genera which have not hitherto been described. 



Conferva spinigera, from Monte Video. 



Herpochceta, a new genus proposed for the reception of the filiform 

 Caulerp(£. 



Sphacelaria brachygonia, from St. Catharine^s. 



Mesoglaa Brasiliensis , from Rio de Janeiro, remarkable for its car- 

 tilaginous substance. 



Irid(Ba Cutlerice = Halymenia Cutleriae, Mart, and Her. 



The other new species have been characterized elsewhere, as stated 

 at the beginning of this notice. 



PROCEEDINGS OF LEARNED SOCIETIES, 



ZOOLOGICAL SOCIETY. 



May 23, 1843.— R. C. Griflith, Esq., in the Chair, 

 Mr. Cuming communicated the following paper by M. R^cluz, 

 being descriptions of various new species of Shells belonging to the 

 genus Nerita, from his collection. 



* It is to be observed that these observations were written before the 

 publication of Kutzing's ' Phycologia,' who has given figures which illustrate 

 admirably the foregoing observation. The only difFerence that 1 can per- 

 ceive is, that he figures a system of smaller filaments interposed between 

 the larger axillary filaments, and Kiitzing seems to consider the union of 

 the filaments more intimate than is described by Dr. Montag^ne. Kiitzing 

 has figured the recurrent filaments in Mesoglcea, though he has not pointed 

 attention particularly to them, but in other genera he has exhibited and de- 

 scribed this peculiar structure very distinctly. 



Ann. §• Maff. N. Hist. Vol. xiii. 2 C 



