1900] MICROSCOPICAL JOURNAL. 109 



odiscus, Chaetoceros, Asterornphalus, and Dichtyotha,with 

 fragments of separated rods of a singular organism with 

 which we were unacquainted, and which made up a large 

 proportion of the finer matter of this deposit. Mixed with 

 the diatoms there were a few small Globigerinae, some of 

 the tests and spicules of Radiolarians,and some saud par- 

 ticles ; but these foreign bodies were in too small propor- 

 tion to affect the formation as consisting practically of 

 diatoms alone. On the 4th of February in lat. 52° 29' 

 S., long. 71° 36' E., a little to the north of the Heard 

 Islands, the tow-net, in dredging a few fathoms below 

 the surface, had come up nearly filled with a pale yellow 

 gelatinous mass. This was found to consist entirely of 

 diatoms of the same species as that found at the bottom. 

 By far the most abundant was a little bundle of silicious 

 rods (pi. Ill, Fig. 5.) fastened together loosely at one end 

 separating from one another at the other end, and the 

 whole buddle loosely twisted into a spindle. The rods 

 are hollow, and contain the characteristic endochrome of 

 the Diatomace®." These were Synedra jeffreysii, and S. 

 thalassiotrix Cleve. 



Synedra jeffreysii and Coscinodiscus asteromphalus 

 are cosmopolitan, be it at the equator or at the poles ; and 

 I think they can be said to have been derived from Syned- 

 ra ulna and Melosira varians in fresh-water. Synedra 

 jeffreysii is Synedra fasciculata, C. A. A., which is a Dia- 

 toma fasciculata C. A. A., and is found everywhere in 

 the ocean. I lately have it from lat. 60° N. in Alaska, 

 being engaged in working up the Bacillaria from the far 

 north, Alaska, in lat. 60° N., for the U. S. Experiment 

 Station, Agricultural College, Brooking, S. D. These were 

 sent to me by Mr. D. A. Saunders, botanist and entomol- 

 ogist and they show that Synedra facisculata, C. A. A., is 

 an extremely cosmopolitan form. 



WANTED. — To exchange diatomaceous earth. C.W.Smiley. 



