76 E. GROVE AND O. STURT ON 



Triceratium papillatum, n. sp., Gr. and St. — Valve small, 

 with deeply concave sides, and enlarged rounded ends, slightly 

 inflated, from which project prominent nipple-shaped processes. 

 Centre inflated. Surface of valve dotted with scattered grannies, 

 with a few stout spines interspersed on the central portion. 

 Length of side, -003". Very rare. (PI. VI., Fig. 14.) 



For the specimen from which the figure is taken we are in- 

 debted to the kindness of Herr Weissflog. 



T. bimarginatum, n. sp., Gr. and St. — Valve small, with 

 straight sides and slightly rounded angles bearing distinct cir- 

 cular nodules. Central part elevated, bounded by a margin of 

 closely-set puncta, which form an inner triangle, having sides 

 parallel with the outer margin. Length of side '0014*. Not 

 frequent. (PI. VI., Fig. 15.) 



T. auliscoides, n. sp., Gr. and St. — Valve small, with rounded 

 angles and mastoid processes resembling those of Auliscus. 

 The sides are produced into obtuse angles between the processes 

 giving an hexagonal appearance to the whole form. Surface 

 minutely punctate with markings like those of Auliscus pruinosus. 

 There is an indication of an umbilicus, and the angles are isolated 

 by an indistinct clear space, giving to the central markings the 

 form of a concave triangle. Very rare. (PI. VI., Fig. 16.) 



We are indebted to W. J. Gray, Esq., M.D., for the specimen 

 from which the figure is taken. 



T. montereyii, Brightw. (" Prit.," p. 856, also "Q.J. M. S.," p. 

 251. PL 4, Fig. 18). — Not common, but typical. 



Aulacodiscus crux, Ehr. — A form of this with three processes 

 has been observed. A small variety with two processes is not 

 infrequent, which is not unlike A. probabilis, A. Sch., but 

 seems to belong to this species. 



A. margaritaceus, Ehr. — A beautiful form of this has been 

 brought to our notice by F. Kitton, Esq. The centre is deeply 

 depressed, and the exterior elevated after the manner of Gras- 

 pedodiscus elegans. The diam. is "0095", it has six processes, and 

 is otherwise quite typical. 



A. angulatus, Grev., a variety with four processes, is not very 

 rare in the lighter density. 



Hemiaulus amplcctans, n. sp., Gr. and St. — We place this pe- 

 culiar form in Hemiaulus solely on account of the general 

 resemblance it bears to some species of that genus. 



