OF C0NCH0L0C4Y. 167 



7. Obolella chromatica, Bill., from Billings. 



8. Centronella, Bill. ; showing the loop. 



9. Loop of Magasella (? var.) Icevis, Dall. ; twice nat. size. 



10. Side view of same, enlarged. 



11. Profile of apoph^'ses of ? Magas ijatagonica, Gld. ; en- 

 larged twice nat. size. 



12. Interior of haemal valve of the same enlarged one-half. 



13. Magasella (? var.) laivis, Dall. ; twice nat. size. 



Plate 7. 



Fig. a. Interior of neural valve of Waldheimia Maphaelis, Dall., 

 showing muscular impressions. 



b. Interior of hgemal valve of do., nat. size. 



c. Side view of Waldheimia Raphaelis, Dall. ; nat. size. 



d. Anterior view of do. 



e. Profile of loop of do,, with one of the crura and part of 



the left hnemal process removed, to show outline of 

 septum. 



f. Haemal valve o^ Laqueus calif ornicus, showing the loop; 



reduced to one-half nat. size. 



g. Profile of loop of Laqueiis suffusus, Dall ; magnified 



three times, linear. 



h. Laqueus suffusus, Dall., nat. size. 



s. Interior of haemal valve of do., magnified. 



Plate 8. 



Fig. 1. G-lottidia albida, Dall. ; nat. size. 



2. " " " interior of neural valve, nat. 

 size. 



3. a, section of do. near beak, magnified, b, c, section of 



lamellje. 



4. Section of lamella magnified 500 diameters, showing 

 the dark horny layers and white calcareous layers. 



5. Section of thickest part of valve, same power, showing 



the layers. 



6. Section of external horny layer, magnified 900 diame- 



ters, showing fibrous structure. 



