LEWIS, OX DIATOM ACE.E. 159 



Interspaces of the canaliculi strongly punctate. Central por- 

 tion similar in outline to that of S. ornata, elevated above the 

 surface of the valve and coarsely striate. Length of valve 

 •006 a -010. 



The striking similarity in outline and number of canaliculi 

 of this to the last-described species, together with the corre- 

 spondence in both of the arcuate, striated bands, at first led me 

 to regard these forms as merely different aspects of the same 

 frustule (valve) ; but after careful examination of several 

 detached valves, by reversing the slides and other manipula- 

 tions, I am led to believe that they belong to different species. 

 Both are very striking and showy forms, more particularly the 

 last, whose strongly marked intercostal puncta, and the 

 generally ornate character of its valve, make it a singularly 

 beautiful microscopic object. S. Febigerii is pretty generally, 

 but not abundantly, distributed along the Atlantic coast. 

 The first specimens were detected by me two years ago in 

 mud dredged from New London Harbour, sent me by Mr. 

 Febiger, of Wilmington, Del., in honour of which careful and 

 industrious observer 1 have named the species. 



Hab. — New London Harbour, mud ; St. Mary River, mud 

 from oysters. Wharf at Fernandina, and more recently at 

 Cape May salt marshes, by Mr. Febiger. From its wide 

 range of locality it will doubtless prove a common form on 

 the coast. 



4. Surirella ovata, Kiitz, sporangial ? This variety is 

 not uncommon in salt marshes along the Jersey coast, 

 although specimens of the size figured are very rare. A 

 comparison with the typical species will show considerable 

 points of difference, but these become less in frustules which 

 approximate to the normal size, although never altogether 

 lost. It is, perhaps, entitled to rank as a variety of ;S'. ovata. 

 Length of valve '0009 a -0050. 



5. Cymatopleura marina, n. sp. — F. V. linear, slightly 

 inflated ends more or less truncate. V. lanceolate, very 

 acute, undulations from 6 to 13. Surface of valve irregularly 

 punctate. Length of valve '0007 a "00. 



This inconspicuous little form, although not yet found in 

 quantity, occurs at various points along Long Island Sound. 

 As far as is known to the writer, it is the only marine 

 species. 



Hab. — On algse at New London. New Haven and Black 

 Rock Harbours. East River (Mr. Febiger), in mud. 



6. Amphiprora conserta, n. sp. — Frustules adherent in 

 curved bands, often to the number of twelve or more. Frus- 

 tule 5=traight, membranaceous. — F. V. linear oblong, slightly 



