1868.] 439 [Stcdder. 



Section of Microscopy, April 8, 1968. 

 Mr. R. C. Greenleaf in the cliair. Eight members present. 



Mr, C, Stodder read the following re])ort of an inves- 

 tigation of soundings made in ten fathoms of water off the 

 coast of Maine, near Mt. Desert Island, by Mr. C. P. 

 Dillaway : — 



The material is a light brown colored jiasto. On treating it with 

 sulphuric acid, it swelled and effervesced rapidly, giving off an abun- 

 dance of sulphuretted hydrogen — a reaction I never before found m 

 "sounding" specimens. It contains, among a large quantity of sili- 

 ceous sand, a few Dictyoca, a very few fragments of Polyclstina and 

 an abundance of sponge spiculse — an unusually large proportion of 

 them being broken; possibly some of the broken spines m:;}- belong 

 to the Polycistina. 



There arc many species of Diatomacea% but the quantity is very 

 Small, i)crha})s not more than one per cent, of the bulk. I have iden- 

 tified : — 



Nitzchia hniceolata. Pleurosigma delicatulum. 



Pinnidaria (Navieula) peregrina. " angulatum? var. 



Navieula Smithii. . Actinoptychus senarius. 



" lyra. Dieladia capriulus. 



" retusa,. Biddulphia aurita. 



Cocconeis scutellum. Grammatophora angulosa. 



" major. " ? 



Coscinodiscus linearis. Gomphonema curvatiuu. 



" radiatus. Rhabdonema arcuatuin. 



" pat;na. Stauroneis aspera. 



.V 



Plagiogramma Gregorianum. 



Melosira sulcata. Rhizosolenia "? 



" (Orthosira) granulatay Periptera "i 



Pleurosigma elongatum. 



The rei)resentatives of most of these species are very few in num- 

 ber, but a single specimen of some having been found. Melosira sul- 

 cata llalis(==Orthosira marina Smith,=Galionella sulcata Elir.) is the 

 most abundant form, about equaling in number all the others, and the 

 specimens are very fine. Coscinodiscus linearis is the next plentiful, 

 and also fine and perfect. Another species of Coscinodiscus occuis, 

 belonging to the group which includes C. stellaris Roper and C. 

 tenuis Bail., but without some of the characters of either these or 

 other described species. The Periptera does not agree perfectly 



