On a Fossil Marine Diatomaceous Deposit from Oamaru, 



Otago, New Zealand. 



By E. Grove and G. Sturt, F.F.R.M.S. 



PART II. 



Plates II., III. 



(Taken as Read, November 26th, 1886.) 



Tricemtium intermedium, n. sp., Gr. & St. — Valve small, "with 

 four rounded angles, and distinct nodules. Sides slightly convex, 

 Centre clear. Rest of surface sparsely dotted except at the margin, 

 which is edged with two rows of closely-set granules. Length of 

 side -0022". Rare. (PI. II, Fig. 1.) 



T. lineatum, Grev. (« T. M. S.,"Vol. xi, p. 75, PI. 5, Fig. 24).— 

 Agrees with Greville's figure, except in having four instead of three 

 clear linear spaces within each angle. Length of side "007 5". Rare. 



A form of this species occurs with two processes only, which we 

 figure as an additional proof of the connection between the genera 

 Trieeratium and Biddulphia. (PI. II, Fig. 2.) 



T. obeswn, Grev. (" T. M. S.," Vol. xii, p. 90, PL 13, Fig. 11.) 

 — Scarce. 



T. crenulatum, n. sp., Gr. & St. — Avery distinct species, frequent 

 in this deposit. Valve with four indentations or " scallops " in 

 each side. Centre and angles elevated, the latter produced into 

 distinct nodules. Umbilicus clear, surrounded by a ring of small 

 granules, from which lines of larger granules, about 8 in *001", 

 extend to the margin. This species varies in outline some speci- 

 mens having concave, and others gibbous margins, with very 

 shallow indentations. A curved line may be seen at the base of 

 the raised angles, particularly in the gibbous forms. Length of 

 side '005". (PI. II, Fig. 3, typical. Fig. 4, forma gibbosa.) 



T. neglectum, Grev. (« T. M. S.," Vol. xiii, p. 7, PI. 2, F. 20). 

 — Rare, but corresponding with Greville's form. 



T. Morlandii, n. sp., Gr. & St. — Valve with slightly concave 

 sides and large prominent ovate nodules, covered with delicate 

 granules. In the centre is a blank space, surrounded by two or 



