NEW GENUS OF DIATOMS. 15 



XII. 



Marine Diatomaceae of Halifax, Nova Scotia. 



As no observations have been recorded upon the marine Diatomaceae of Nova 

 Scotia, I take pleasure in presenting the following list of species found in mud 

 washed from Algae from the harbor of Halifax, N. S., viz : — 



Actinoptycbus sonarius, Ebr. Hyalodiscus subtilis, B. Plate, Fig. 12. 



Ampbiprora constricta, Elir. Navicula (Gjro.sigma) sigma, Ebr. 

 Ampbora stauroptera, B. Plate, Figs. 14, 15. " " cloDgata, Ebr. 



Bacillaria paradoxa, Ebr. (abundant). " " forniosa. 



Cocconeis scutellum, Ebr. " granulata, B. Plato, Fig. 16. 



Coscinodisous (several species). " (Piunularia) clliptica, Ebr. 



Dictyocba fibula, Ebr. " " Ijra, Ebr. 



Dictyoeba speculum, Ebr. " " pcregriua, Ebr. 



Diploneis entomon, Ebr. " " (several undetermined species). 



Diploneis didyma, Ebr. Rbabdonema arcuatum, Kg. 



Gompboneuia minutissima, Ebr. Stauroptera aspcra, Ebr. 

 Grammatopbora serpentina, Ebr. " oblonga, B. Plate, Fig. 17. 



" stricta, Ebr. Synedra sigma, Ebr. 



XIII. 



New Genus of Diatomaceae. 



Toxat'iuiu, Bailey. 



Lorica very long and slender; bases with an undulating outline, swollen in the 



middle, and then contracted into two excessively elongated processes with enlarged 



and rounded ends. Sides with nearly straight parallel edges. Bases transversely 



striate. The sides show the ends of the basal striae. 



Toxariiiiu iinfliilatiim, B. 



Plate, Figs. 24, 25. 

 Sjn. Synedra undulata, B. ms. and specimens. 



This interesting species, the only one of its genus now known, was found by me 

 several years ago, attached in considerable numbers to Sargassum vulgare, in Nar- 

 ragansett Bay. I distributed specimens under the name of Synedra undulata, B., 

 but I now think it should form the type of a new genus, characterized as above. 



The length of T. imdvlala is about 35m., its width at the middle of the base is 

 about hn., and the width of the narrow parts of the base is about Im. 



Habitat : Narragausett Bay, R. I., and Pecouic Bay, near Greenport, New York. 

 At both localities it was found parasitic, like a Synedra upon Sargassum vulgare. 



XIV. 



I cannot close this paper without expressing my thanks to Mr. J. E. Gavit, of 

 Albany, the engraver of the Plate. Whatever fiiults the figures may present ore 

 due to me; for Mr. Gavit has, with untiring patience, industry, and zeal, endeavored 

 to make the Plate as perfect as possible. The figures 5, 12, 26, and 27, are par- 

 ticularly beautiful. Figures 10 and 12 really need a magnifier to see their details. 



