Mr. V. MLii'schkowaky on Calij'oniuin Diatoinn. ."iLj 



varies greatly. If tlie lenser coarseness sliouM provi; to he a 

 constant ciiaractor, tlicn, of conrsc, a .so|)arate variety — var. 

 tesselitUi — could be e.stahlislicd, as the true li. antediluvt'ana 

 of Europe has invariably very coarse alveoli ; but havinj^ 

 seen only one individual of that kind, I regard this case as an 

 accidental one. Therefore the best would be, in my opinion, 

 to unite />'. icsscllatn and /?. Hutrdilnviana in one species. 



IDG. Biddulphia (Triceratium) arctica, Brighfw. Northern 

 California; ]\Ionti.'rey, not rare, [fi., M.J 



l'.>7. Biddulphia (Triceratium) arctica, var. tetragoua, Cniui. 

 Murthcrn Caliiuruia, connnun ; Monterey, rather rare. 

 [G.] 



I'JS. Biddulphia (Triceratium) montereyi, Brii^htw.* San 

 Pi'iir'', rare; Nurthciu Caliluriiia. [(J., .M.] 



19L). Biddulphia (Triceratium) sanpedroana, ^It-r., sp. n. 

 (IM. IV. tig. 27.) San Pedro, not rare. [M.] 



DilTers from B. {AmjJiilttnis) punctata, Grev.f, which is 

 found in Ceylon, by the j)uncla or alveoli being more rounded 

 and not so closely disposed, the margins of the valve not so 

 deeply concave, and the processes less elongated, broader, and 

 more rounded. There seems to be a difference also in the 

 central part of the valve, which in B. punctata shows a well- 

 defined central area with a few scattered granules. 



'Die puncta are sometimes a little larger than represented 

 in my figure, sometimes they are smaller and more distant, 

 but the valve has always about the same shape, its processes 

 never being so prominent and acute as in the type species. 

 The central part of the valve is concave and the concavity 

 has sometimes a quadrangular form with angles opj>ositc to 

 the middle part of the concave margins ; if in such individuals 

 the })uncta are at the same time veiy small, they greatly 

 resemble B.elegans, Grev. B. {^Triceratium) t>anpedroana is 

 no doubt nearly allied to JJ. [Triceratium) antediluviana. 



Kumber of puncta usually i^'b in 001 mm. (t'rom 3 to 1), 

 greatest diameter (along a diagonal) 0OG3-011'J mm., smallest 

 diameter 0049-0-091 mm. 



This diatom is widely distributed all over the Pacific Ocean. 

 1 have found it also in the fossil deposit of Redondo (Cali- 

 fornia). 



200. Biddulphia (Triceratium) unciiuiata, G run. (See Wolle, 

 Dial. Anur. |il. cii. tig. 12.) 



* l.iic. cit. i>l. i. fi^'. I'". t Xof. lit. \<], xliii. lig. 8. 



