NATURAL SCIENCES OF PHILADELPHIA. 65 



Hab. Mud from oysters, St. Mary's river, Ga. Tidal mud from Savannah 

 river. Marsh at Fernandina, Florida. Rare. 



10. Navicula P o w e 1 i i, n. sp. V. Linear, sharply attenuated at subacute 

 extremities, striated ; striae costate, interrupted about their middle by a blank 

 line running from end to end of the valve ; central nodule surrounded by a 

 large lozenge-shaped blank space, reaching to the blank line as above. Length 

 of valve -004 a -006. PI. II. f. 6. 



This species is allied to Navicula 1 i n e a t a Donhin, Mic. Jour., in striation, 

 but not in general characters. 

 Hab. Black Rock Harbor, on algae and on mud. Rare. 



11. Mastogloia an gu lata, n. sp. F. V. Oblong, truncate. V. Elliptical 

 extremities slightly produced ; loculi from 8 to 12 ; striae 36 a 40 in -001, re- 

 sembling those of Pleurosigma angulatum. Length of valve -0014 a "0035. 

 PL II. f. 4 



This species cannot be confounded -with Mastogloia apiculata, from which 

 it differs in its more broadly elliptical shape, the smaller number of its loculi 

 and the angular character of its striation. These specific characters are un- 

 varying. 



Hab. On algae, from rocks off New Rochelle, Bannister's creek. Rockaway 

 tidal mud. Stonington Inlet, on harbor grass, along with M. apiculata and 

 M. lanceolata. Salt marshes at Atlantic, N. Jersey. Salt marshes at Cape 

 May. Common. 



12. Mastogloia exigua, n. sp. V. Lanceolate elliptic ; extremities some- 

 times a little produced; loculi 2 to 5, (commonly trilocular,) arched on the 

 central aspect ; striae obscure. Length of frustule *0005 a - 001. PL II. f. 5. 



Hab. Marsh scum of St. Sebastian river, St. Augustine, Florida. Pier at 

 St. Augustine. Fernandina pier, coast of New Jersey. 



This species occurs quite abundantly at the above localities. Its distinguish- 

 ing peculiarity is the small number and curved outline of the loculi. 



II. Rare and hitherto, in this country, unnoted species. 



1. Cocconeis oceanica Ehr. V. Broadly elliptical, somewhat larger than 

 the variety figured in "Bacillarien." 



Hab. Tidal rocks off New Rochelle, L. I. New London and Bridgeport, 

 attached to algae and sertularia. Common. 



2. Epithemia const ri eta W. Smith. Hab. Mud from St. Sebastian river, 

 St. Augustine, Florida. Common. L. I. Sound. 



3. Eupodiscus Ralfsii W. Smith. Hab. Mud from Black Rock Harbor. 

 Bush river, Del., Mr. Febiger. Rice field mud, Savannah. St. Mary's river, 

 Ga. Common, but not abundant. 



4. Actinophenia splendens Shadbolt. Hab. Delaware river mud. St. 

 Mary's marsh, Ga.- Rare. 



5. Arachnoidiscus Ehrenbergii Bailey. Hab. Long Beach, San Fran- 

 cisco, Cal., on algae, along with Hyalodiscus Californicus. Rare. 



6. Triceratium undulatum W. Smith. Hab. Delaware river mud. St. 

 Mary's river, Ga., marsh. Rare. 



7. Triceratium striolatum Ehr. Hab. St. Mary's river, Ga. Rice field 

 mud, Savannah. 



8. Triceratium pentacrinus Wallich. Hab. Rice field mud, Savannah. 

 Dredgings off Florida. U. S. Coast Survey. St. Mary's river. Rare. The 

 4 and 5-sided varieties are the only ones I have met with. 



9. Campylodiscus costatus Ehr. Hab. Delaware river mud. Rare. 

 1861.] 5 



