688 Transactions of the Society. 



C. Gazellse Janiscb. — Diameter of valve (as far as can be ascer- 

 tained from fragments), 1"8 to 1*9 mm., tbus exceeding even 

 C. regius in size. Centre smootb, bke C. nohilis, but bordered by 

 a circle of small spines similar to tliose occurring in C. regius; tbe 

 radiating rows of puncta are somewbat closer tban tbose in tbat 

 species (6-7 in •01 mm.). Upper edge of valve smootb, precisely 

 as in C. regius. Near tbe margin numerous sbort irregularly 

 curved striae (consisting of darker puncta) are visible. 



' Gazelle' sounding, No. 125, 30' 53' S. lat., 177° 6' E. long. ; 

 deptb 4151 metres. 'Cballenger' sounding, station 265, deptb 

 2900 fatboms. Tbis form was named by Herr Janiscb in remem- 

 brance of tbe scientific expedition made by tbe German sbip, 

 * Gazelle,' in tbe years 1874-1876. PL XXI., Fig. 8 (*p). 



I bave found fragments tbat can only belong to tbis species 

 in a sample of Nottingbam deposit in wbicb it was not un- 

 common. 



C. regius was originally distributed under tbe MS. name 

 of Rex. It is undoubtedly tbe largest diatom, excepting C. Ga~ 

 zellfB, bitberto discovered. C. regius was first found, in tbe Bay 

 of Bengal in 1857, by Dr. Wallicb. Tbe ligbter portions of one 

 of tbe ' Cballenger ' dredgings (station 265, deptb 2900 fatboms) 

 consist almost entirely of fragments of tbis species. C. nohilis 

 is by no means an uncommon form; I bave found it in tbe 

 stomacbs of Noctilucse collected at Gorleston Pier (Norfolk), asso- 

 ciated witb C. concinnus, for wbicb it is sometimes mistaken. I 

 bave also seen it in gatberings from Harwicb, Hong Kong, 

 Arafura Sea, and Sea of Java. It differs from G. concinnus in its 

 large smootb area and its more distinct puncta and radiating lines. 

 Tbe rows of puncta in C concinnus terminate in a small central 

 rosette of small cells. C. tenuis Bailey * is undoubtedly tbe same 

 species, f as is C. centralis of Scbulze. 



In 'Casp. See Algen,'Herr Grunow says, "Allied to Podosira 

 hormoides is a form wbicb I provisionally call Htjalodiscus 

 maximus. It is witbout doubt identical witb Cyclotella maxima." 

 In tbe communication now received are tbe following additional 

 remarks. 



Podosira maxima (Kiitzing) Grunow, in Cleve and Grunow's 

 'Arctic Diatoms.' Cyclotella maxima Kiitz. ad specm. autbent., 

 Hyalodisciis maximus Grun. I. c. ex parte, Actinoptyclius inter- 

 punctatus Brigbtwell. — I bave adopted witb some besitation 



* ' Boston Journ. of Nat. History,' vol. vii. p. .393, pi. vii. fig. 9. 



t Bailey (/. c.) also says, " tliat he has seen from tlie same locality (Para 

 River) a similar form with three processes." (I liave seen C. radiatns with similar 

 processes.) This is no donbt the same species as that found in the Java Sea. 

 The so-called processes are not constant, and are pi obably only abnormal growths ; 

 see Prof. H. L. Smith, ' Amer. Jour, of Micr.,' Ang. 1877.— F. K. 



