304 Transactions. — Geology. 



be ringed. Any of the various cements described will do. I 

 have, myself, used Judson's gold-paint or Kitten's cement, the 

 formula for which is equal parts of red-lead, white-lead, and 

 litharge ground together to a fine powder, and mixed when 

 required for use with a little gold-size. 



DESCRIPTION OF PLATES XVIII-XXIII. 



Plate XVIII. — Map of Oamaru and district, showing the diatom outcrops or 

 faces at Cormack's siding, Jackson's, Bain's, and Allen's farms. The 

 dotted lines show the area of diatomaceous deposit as mapped out by 

 Mr. Isdaile. Diatom earth has also been ploughed up in Cave Valley 

 and on the east side of the Waiareka Creek. None has, however, yet 

 been found on the west side of the creek, nor on the hills near To- 

 tara Round Hill. A small deposit occurs just where the road crosses 

 the railway-bridge to Enfield, but it is of no importance, and is much 

 mixed up with the calcareous debris of the disintegrated limestone. 



Plate XIX. has been described in the letterpress. (See p. 295.) 



Plate XX.— All these figures represent the diatoms of the different deposits, 

 with their characteristic appearance, as shown under a power of about 

 75 diameters. To have been quite accurate, those in Jackson's and 

 Bain's should have been shown rather larger. 



Fig. 1. Deposit from Cormack's siding. 

 „ 2. „ H. Allen's farm. 



„ 3. „ Totara estate. 



„ 4. „ Jackson's farm. 



„ 5. „ Bain's highest deposit. 



„ 6. Foraminifcra from Jackson's and Bain's farms. 



Plate XXI.— 



Fig. 1. Triceratnim rcnulosmn, var. major, Gr. and St., n. sp. 

 „ 2. „ cosciiwides, Gr. and St., n. sp. 



„ 3. „ rugosum, Gr. and St., n. sp. 



„ 4. „ dobrceammi, var. nova-zealandica, Gr. and St., 



n. sp. 

 „ 5. Trinacria simulacrum, Gr. and St., n. sp. 

 „ 6. Triceratium morlandii, Gr. and St., n. sp. 

 „ 7. „ oamarucnsc, Gr. and St., n. sp. 



Plate XXII.— 



Fig. 8. Triceratium crenulatum, forma gibbosa (?), Gr. and St., 

 n. sp. 

 9. „ „ Gr. and St., n. sp. 



„ 10. UutikLria radiata, Gr. and St., n. sp. 

 „ 11. Actinoptyclms vulgaris, Schum., var. maculata, Gr. and St., 



n. sp. 

 „ 12. Auliscus oamariLcnsis , Gr. and St., n. sp. 

 „ 13. Aulacodiscus janiscldi, Gr. and St., n. sp. 

 „ 14. Eunotogramma ivcissei, Ehr., var. producta, Gr. and St. 



(Valve.) 

 „ 15. Eunotogramma ivcissei, Ehr., var. producta, Gr. and St. 

 (Frustule.) 



