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XXXIV. — New Si:)ecies and Varieties of Biaiomacex from the 

 Caspian Sea. By A. G^runow, Hon. F.Pi.M.S. Translated 

 with additional Notes by F. Kitton, Hon. F.R.M.S. 



{Bead 11th June, 1879.) 

 Plate XXI. 



Ampliora (angusta Greg. var. ?) ohlongella Grunow. — A. minuta, 

 a latere primario angusta, oblonga, polls rotundatis, valvis cymbi- 

 formis obtusiusculis, ventre piano, linea media subrecta margine 

 inferiori approximata, striis dorsalibus subradiantibus 14-16 in 

 •01 mm., ventralibus brevissimis. Longit. '032- •036 mm.; latit. 

 •008- •0010. 



Harbour of Baku, common. 



Its relationship to the very imperfectly figured A. angusta 

 Greg, is very doubtful. The striae on the ventral portion appear 

 to bo much longer — Gregory gives 17 in the •Ql mm. ("about 44 

 in -001" ") ; still slighter is its resemblance to A. nana Greg., with 

 19 striae in '01 mm. The ventral striae also appear to be shorter. 

 The relationship of these forms is therefore scarcely probable. 



A. lineata Greg. var. suhconstrida Grun. — Frustulis in media 

 parte levissime constrictis, striis punctatis dorsahbus 15 in •Ol mm., 

 ventralibus tenuissimis. Longit. •035-^045 mm. ; latit. •Oil. 



Harbour of Baku, common. 



I have frequently met with a more strongly constricted Am- 

 phora in diatom gatherings from Tahita (Tonga and Samoa Islands), 

 which I Hkewise consider to be a form of A. lineata and have 



DESCRIPTION OF PLATE. 

 Fig. 1. — Coscinodiscus nohilis Grun., from Java, ^42. 

 „ 2. — a, Podosira maxbna Kg., from Peru, a^a. 



{Cydotella maxima, authentic specimen.) 

 6 c, Structure of inner and marginal portions of valve. 

 d. Two frustules of P. maxima, with the connecting membrane, showin' 

 the granular endochrome, -5^°. ' 



„ 3. — P. stoUulifera Grun., Monterey deposit, aofl_ 

 ,, 4. — a, Podosira ambigua Grun., St. Paul, s.op_^ 



b c, Structure of the inner portion and the margin of the valve, '"" . 

 „ 5. — a b, Hyalodiscusscoticjis (Kg.) Giun., S-OQ^ ^ 



(Cyclotella scotica Kg., authentic specimen.) 

 (Fig. a, dried specimen with endochrome.) 

 c. Structure of valve, 1^12. 

 „ 6. — a, P. A]-gus Grun., California, a|£. 



6 c, Structure of inner portion and margin of valve, '- i°. 

 „ 7. — a, P. hormoides, Montague, Lima, ^e^. 



b, Structure of valve, ^-^. 

 „ 8. — Small fragment of outer portion of Coscinodiscus Gazelkc, i^a. 



