KONGL. SV, VET. AKADEMIRNS HANDLINOAH. BAND. 27. N:0 3. 148 



however, occur between these types, and I see no reason for splitting up the genus on this 

 account. Among other Naviculoids no kindred forms are known, except in the genus CVx^cfineis of 

 which some species seems to be degenerate forms of Mastogloia. 



The species of Mastogloia live in gelatinous mammillate masses, the formation of which 

 seems to have some connection with the loculi. A few only inhabit perfectly fi-esh water. Home 

 as M. Smithii, M. rUipfica, M. crifjua, M. laiiceolata are abundant in brackish water. A. small 

 number of species are found in the Arctic seas, but the majority occur in tropical seas. 



I have placed the small Biadesmis gaUica W. Sm. in Mastogloia, on the supposition that 

 the marginal puncta of this species are loculi, which is not easy to decide as the form is so ex- 

 cedingly small '). 



2. 

 3. 

 ^ 1 Valve linear with cuneate ends M. Grevillei W. Sm. 



Artificial hrij. 



^ J Structure doulile, of costsp. anel puncta 



\ — simple, of puncta onlj' 



2 ■! 



I — elliptic-lanceolate M. Castracanei Pant. 



„ J Puncta arranged in decussating rows 4. 



t — not - 22. 



. i Ends subacute, more or less rostrate 5. 



' I — broad, rounded 13. 



J. j Stria; abont 22 in 0,0 1 mm 6. 



•'■ 1 - - 13 - - 8. 



Loculi 9 in 0,oi mm M. clecussata Grun. 



M. delicatula Cl. 



- 3 to 4 - ■ 7. 



Valve with longitudinal furrows M- sulcata Cl. 



— without — — M. Kjelhnanii Cl. 



( End; 



( — subacute , M. Grovei Cl. (iH. Baliamensis Cl,, M. Jelineckiana Geun.). 



Loculi lunate M. Rhombus Pet. 



quadrate or rectangular 10. 



, , Median loculi larger than the others M. angulata Lewis. 



I Loculi 9 in 0,oi mm 



G. I — t; — — 



M 



„ I Ends rostrate 9 



o. 



j Medi£ 



' l — not — — — 11- 



,. I Terminal loculi larger M. rostellata Geun. 



^^- \ - - not - 12. 



I Rim of loculi reaching to the ends M. asperula Grun. 



" I — — n 



,s.{ 



ot — — — M. Szontaghii Pant. 



Loculi lunate 14. 



— quadrate IC 



I Loculus single unilateral M. bmofata Grun. 



I Loculi few 15- 



.^ j Central area a transverse fascia M. Crueicula Grun. 



■'■ ) — — not — — M. fimhriata Btw. 



j Median line between two rows of puncta 17. 



' \ — — not enclosed between rows of puncta 18. 



I Puncta along the median line rounded M- Wrightii O'M. 



I — — — — — elongated . . . . ■ M. Barhadensis Grev. 



I Transverse rows of puncta ending near the margin in double rows of small puncta . 19. 

 ^^- i - _ _ not - - - - - - - . 20. 



( Rows of puncta 5 to G in 0,oi mm M. Clevei Grun. 



\ 8 — M. splendida Greg. 



') The following monograph was already completed, when the plates 185 to 188 of A. Schmidt's Atlas were issued, 

 in which a considerable number of Jlastogloise are figured. Before printing this monograph I have completed the text with 

 ([uotations, but I could not change the artificial key, as most of the new species are not represented in sufficient detail for 

 being admitted into the system. The reader will find at the end of this monograph a list of the new species, which I am 

 unable to identify with known forms. 



