better known as the Coccolith. 189 



{I. c. fig. 7j d) I have not yet seen, but can easily conceive that 

 this is a still more developed form of the sporangium or cocco- 

 sphcrc, perhaps undergoing dehiscence. 



By the use of acetic acid I have not been able to determine 

 whether the frustules are on the inner or on the outer side of 

 the membranous cell of the coccosphere. If the latter, then 

 perhaps the outer cell of the sporangium is fugacious, leaving 

 the frustules attached to the inner one, as in Synura uvella, Ehr. 

 (' Infusionsthiere,' Taf. 3. fig. 9 ; and Pritchard, ' Infusoria,' 

 pi. 20. figs. 29, 30). We, unfortunately, know much more 

 about the different forms of matured sporangia than we do of 

 their subsequent development ; so that our means of com- 

 parison here are necessarily very restricted. 



I prefer the name of " Melohesia " for these cells, as this 

 associates them with the calcareous Algse, to which they ap- 

 pear to me to be most intimately allied, and for which family 

 Lamouroux first proposed the name. The two forms cannot 

 be considered to belong to a dioecious species, because both 

 have their respective coccospheres. 



Thus we have auother organism in the Laminarian zone 

 liei^e which descends to the greatest depths of the Atlantic 

 Ocean, to furnish food for the lower animals of that region, as 

 it does for those at the borders of the sea. I have already 

 pointed out, in the last number of the ' Annals,' the way in 

 which the pachytragian shore-sponges are continued down 

 into the deep sea throiigh SteUetta ( Tisiplionui) agariciforviis^ 

 Sdt., = WyviUe-Thomsonia Wallichn, Wright, — to Avhicli I 

 might have also added the Esperiadaa, culminating in the 

 great shrub-like branching form noticed by Dr. Carpenter, of 

 which a specimen was sent to the British Museum ; and now, 

 while examining the portion of deep-sea mud to which I have 

 alluded for coccoliths, I observe a representative of the Geo- 

 didee in the presence of one of their little siliceous balls with a 

 surface-pattern differing from any with which I am acquainted. 

 Thus, perhaps, when all is told of this remarkable and remote 

 locality, we may find still more instances of the connexion of 

 living organisms on the borders of the sea with those in the 

 greatest depths of the Atlantic Ocean. 



Had Prof. Huxley had time to give his attention spe- 

 cially to the coccoliths, with the other advantages afforded 

 by a sea-side residence, his antecedents show that he probably 

 would have anticipated me in much more than I have above 

 stated. 



