KONÖL. SV. VEt, AKADEMIENS HaNDLINGAS. BAND. tö. N:0 4. 81 



The septa are thicker and inore compact on the inner edge, their outer part 

 being so taken up with chaniiels, that they are absorbed, so to speak, in channelwalls. 



The subdivisions of the chambers in the younger stages are more irregular and 

 spongelike. 



It is very common, both on the chalkbottom and in the coralline-gravel, and at- 

 tains a length of 6 and a breadth of 4,5 mm. 



Fig. 167: View of its flat side. 



Fig. 168: » » » edge. 



Fig. 169: » » » aperture-side. 



Fig. 170: Vertical section in the flat median plane; in the background of the 

 broad vestibules the first set of channels (or shallow chatnbers) shew their four rarai- 

 fications, the upper couples being half hidden by the slanting septa. 



Fig. 171, tab. VI: Vertical section through the median transverse plane; the 

 interstices between the septa, the vestibules and the channels of sets N:ris 2 and 3 

 and tlie pore-canals are represented. 



Fig. 172: A chamber, horizontally opened shewing the walls and subdivisions of 

 the channels of the different sets. 



Textularia pupoides dOrb. 



Tab. VI, figg. 173—180. 



The close affinity between the genus Gaudryina d'Orb. and Textularia has long 

 ago been proved by Messrs. Parker, Jones and Carpenter, and in fact there is no 

 reason at all for their generic distinction. Indeed evidence may by and by be adduced 

 to shew, that each Textularia-species has its Gaudryina-development, just as it has its 

 Bigenerina form. But ad interim we must consider it as a distinct species, although 

 there is no want of intermediate links, for sometimes the young tri- or multiserial 

 stage is reduced nearly to nothing, and the biserial arrangement occupies almost the 

 whole shell; as for instance in Gaudr. chilostoma Rss. 



Our form comes next to Gaudr. insecta Stache, Gaudr. rugosa d'Orb. and Gaudr. 

 prcelonga Stache. It is often very irregular with small protuberances and wrinkles 

 being nearly square in transverse section. Its early stage is often 3 — 5-serial. At 

 other times it is quite regular, smooth and cylindrical with the inultiserial stage reduced 

 to 1 — ^2 rows of chambers. Sometimes it is very slender and produced. 



It is always agglutinated of the finest chalkdust, without siliceous sand. It oc- 

 curs not very comraonly both on the chalkbottom and in the coralline-gravel. 



Figg. 173—174: the Avrinkled form. 



Figg. 175 — 176: transverse section of its 4 — 5 serial stage. 



Fig. 177: smooth regular form. 



Fig. 178: transverse section of the same. 



Fig. 179: slender produced form. 



Fig. 180: transverse section of its first stage. 



K. Sv. Vet.-Akad. Hancll. Bd. 19. N:o 4. 1 ' 



