120 p. T. cleVe, synopsis of The NAVlCULom WATOMS. 



and oblique strise almost equidistant, 19 to 20 in 0,oi mm. — Fleur. rectum Donk. T. M. S. VI 

 p. 23 PI. Ill f. 6. Amphiprora Ealfsii Aknott M. J. VI p. 91 (1858) ad spec, authentica. DonMnia 

 recta Y. H. Syn. p. 119 PI. XVII f. 9. Per. IX f. 4. P. Lorensii Grun. Verb. 1860 p. 558 

 PI. VI f. 4. Per. VII f. 17. 



Marine: North Sea! Mediterranean Sea! Adriatic! Labuan! China! Port Jackson! Florida! 



Var. intermedia Per. (1891). — V. more lanceolate, with less asymmetrical ends. — DonMnia 

 recta var. int. Per. p. 30 PL IX f. 7, 8. 



Marine: Cherbourg (Per.), Firth of Tay! 



Var. Thumii Cl. (1891). — L. 0,i to 0,i3; B. 0,oii to 0,oi2 mm. T.S. : L.S. ^V^-i, -%> ^Var 

 in 0,01 mm. — DonMnia Thumii Per. p. 30 PI. VII f. 28, IX f. 10. 



Marine: Balearic Islands! Seychelles! Sumatra! 



Var. minuta Donk. (1858). — Smaller. L. 0,06; B. 0,oi2 mm. Striae 19 in 0,oi mm. — 

 Fleur. minutum Donk. T. M. S. VI p. 24, PL III f. 8. DonMnia min. Ralfs in Pritch. Inf. p. 921 

 (1861). Per. IX f. 9. 



Marine: Newcastle! Firth of Tay! 



27. O. lineare GtRun. (1880). — V. narrow, linear, almost straight, unilaterally narrowed 

 towards the ends. L. 0,i7 to 0,2 6; B. 0,oi to 0,oi5 mm. Median line sigmoid, strongly excenti"ic. 

 T.S. : L.S. -''/24, -V26 i*! 0,01 mm. — Rhoic. lineare Grun. A. D. p. 59. Per. IX f. 11 (median line 

 incorrectly represented as central). 



Marine: Adriatic! Seychelles (Grun.), Port Jackson! Colon! 



Var. longissima Cl. (1881). — V. very narrow, with obliquely rounded ends. L. 0,i6 to 

 0,17; B. 0,007 mm. T.S. : L.S. is/j,, 27,2 in 0,oi mm. — Fleur. (DonJc.?) long. Cl. N. R. D. p. 6 

 PL I. f. 8. Per. VII f. 16. 



Marine: Mediterranean Sea (Gulf of Naples, Balearic Islands)! 



28. G. angustnni Donk. (1858). — V. very convex, thin, linear, with unilaterally attenuate, 

 acute ends. L. 0,i26 to 0,i4; B. 0,oi5 mm, Median line diagonal in the middle and then marginal. 

 T.S. : L.S. 28/,„ in 0,oi mm. — Fleur. angustum Donk. T. M. S. VI p. 24 PL III f. 9. DonMnia 

 angusta Ralfs "in Pritch. Inf. p. 921 (1861). Per. IX f. 3. 



Marine: England (Donk.), Balearic Islands! 



Var. sumatrana Cl. — Less convex. L. 0,i4; B. 0,oi8 mm. T.S. : L.S. -7.2, in 0,oi mm. 

 Median line less excentric. 



Marine: Sumatra (Deby Coll.)! 



29. P. (Rhoicos.) compactum Grev. (1857). — Frustule arcuate, with dissimilar valves. 

 V. short, linear, unilaterally attenuated to the obliquely rounded ends. L. 0,089 to 0,4; B. 0,oi5 to 

 0,05 mm. Upper valve with straight diagonal, median line T.S. : L.S. i*/22i 'V231 '"/an "/20 in 0,oi mm. 

 Lower valve with strongly excentric and sigmoid median line. T.S. : L.S. '^/j,, "/jg, "/j.,, '%2i 

 '9/23, ^^|.,^ in 0,01 mm. — Loioer valve: Fleur. comp. Grev. M. J. V. p. 12 PL III f. 9. DonMnia 

 comp. Ralfs in Pritch. Inf. p. 921 (1861). Ehoic. comp. Grun. M. M. J 1877 p. 182. Per. 

 p. 33 PL X f. 7, 8. Rhoic. oceanicum Per. 1. c. f. 5, 12, 15. Rhoic. corsicanum Per. 1. c. Rhoic. 

 Antillarum Cl. West. Ind. D. p. 9 PL II f. 14. Fleur. Smithianum Castr. Voyage Challenger D. 

 p. 38 PL XXVIII f. 6? DonMnia antigua Grove and Sturt J. Queck. M. Cl. Ill [2] p. 133 (1887)? 

 — Upper valve: Rhoic. Reichardtianum Grun. Hedwigia VI p. 11 (1867). M. M. J. 1877 p. 181 

 PL CXCV f. 19. Rhoic. compactum Per. p. 33 PL X f. 6, 8, 10, 13. 



Marine: La Rochelle (Petit Coll.)! Mediterranean Sea! Adriatic! Red Sea! Sumatra! Philip- 

 pines! Port Jackson! Samoa! Tahiti! Galapagos Islands! Honduras (Grun.), West Indies! 



Var. constricta Grun. (1877). — V. slightly constricted in the middle, with subcuneate ends. 

 L. 0,13; B. 0,02 mm. TS. : L.S. '7,9, '720 in 0,oi mm. — Rhoic. {Reichardtii var.?) constr. Grun. 

 M. M. J. 1877 p. 181. 



Marine: Honduras (Grun.)! Adriatic (Grun.)! 



