^'^ Greville, on New Diatoms. 



situated. The extent of the deposit is not known; but, like 

 den h'"" ?f^^^«^^^/t is probably large both in surface and 



form. . W ' '' '^^^^^'^ ^ ^'^^^ ^^^'^^^y «f diatomaceous 

 torms but vanous new and interesting species have already 

 been observed in It. ^/;^,^ /^ -^ ^ 



Stictodiscus Buryanus, n. sp., Grev.-Pore-like puncta at 

 the marginal extremity of each compartment, forming a 

 pyramidal group; rays 30; diameter -0040" (PI IV fio- i) - 

 Hab. Deposit at South Naparima, Trinidad; Mrs. Bury /' 

 Ihe disc of this superlatively beautiful diatom is trans- 

 parent and gently convex, remotely dotted over with lar-e 

 clear, pore-hke puncta, exhibiting also the shadows of puncta 

 belonging to the ower valve. The marginal groups coasist 



thanYalfX" /^^r'^'i^f ^^"^^ ^''^'^'^ arf free' for more 

 than half their length, and then, after anastomosing, become 

 faint and inconspicuous before reaching the centre When 

 the'di o"'' 'T '-^.^-rately focussed, the plicate character of 

 coLn^uousTfi'i^ ^^^^^^-l^-gi^S the focus it becomes 

 conspicuous (fig 2). A single specimen only has hitherto 

 been observed, for which my cabinet is inLbted to the 

 generous kindness of its discoverer ^"tieDted to the 



Sttctodiscus Bota (Ehr.), Grev.-- Disco amplo superficie 

 maequaliter papillosa, rapillis centralibus majoribus, m'ar^ne 



"^^^^Z^^^ -'''''- ^-" -^-»--^^- -te;yallo?um 

 ^ .^V ^:i^l S^m^^^^- "-'''•' ^^^^ ^- ''' ' 



Hab. Southern Ocean. 



ver?cle^a!rthatir^ '^'" diatom by Ehrenberg, indicates 

 very cleaily that t is a genmne Stictodiscus. The valve is 

 very large the radiating liues much shorter than in the other 

 species; the puncta within the compartments disposed appa 

 rently, in an irregular double series,%nd extend as far asT^ 

 termination of the lines. The whole central space is covered 

 with numerous large puncta, as in the precedinTspecies 



St^ctod^scus Rotula (Ehr.), Grev.-pWcta equ^r remotely 

 scattered over the blank centre of the disc, tho^se wiS th'e 

 compartments irregularly (?) disposed ; ra^s 20 

 ^B^scoplea? Rotula, Ehr., ^ Microgeol.,^ pi. xxxv, a. 22, 



' feti^difpS:^ '^'- ^'- ' ''-^ ^^^^ - ^-^^- 



Hab. Southern Ocean. 



