144 



E. GROVE AND O. STDRT ON 



horns terminating in spines ; while the other has inflated ex- 

 tremities, but without horns or spines. (PI. XIII, Fig. 43). 



77. amplectans, var. major. — Differs from the typical form (supra, 

 p. 76, PI. 6, Fig. 17) in the greater length of the valve, and in 

 being covered with granules instead of being hyaline. (PI. XIII, 

 Fig. 44.) 



H. augustus, Grev. (" T. M. S.," Vol. xiii, p. 30, PI. 3, Fig. 12) — 

 Several specimens have been observed, which agree with Greville's 

 figure, excepting that there is only one spine, projecting inwards 

 at the extremity of each horn. 



// ? te unicornis, Grev. — We figure an example which has occurred 

 to us of opposite valves of this species in conjunction, showing that 

 the connection between the frnstules is effected by an interlacing 

 of the horns, and not, as in the true Hemiaulidoe, by the junction 

 of terminal spines or claws. (PI. XIII, Fig. 45.) 



Note. — This being so, it appears that Greville was right in his 

 doubt as to whether this and other allied species described by him 

 (" T. M. 8.," Vol. xiii, p. 29) rightly belong to Hemiaulus. "We 

 take the opportunity of correcting an erratum on page 11, supra, 

 where " tenuicornis " is printed " tenuiformis." 



Trinacria simulacrum, n. sp., Gr. and St. — This singular form 

 is frequent in the deposit, but further investigation is required 

 before it can be ascertained whether it really belongs to the Genus 

 in which we placed it provisionally. It has been suggested that it 

 may be an inner or secondary valve of T. Kinherii, A. Sch. 

 ("Atl.," PI. 112, Fig. 21), but we think, if this were so, we should 

 have met with the true valves of that species ; which has not been 

 the case. (PI. XIII, Fig. 46.) 



T. ventricosa, Gr. and St. (supra, p. 63, PI. 5, Figs. 1, 2, 3). 

 — Having, through the kindness of Dr. Stolterfoth, obtained a 

 complete frustule of this form, we give a figure showing a pair of 

 primary and secondary valves in situ. (PI. XIII, Fig. 47.) 



Coscinodiscus centralis, Greg. (" G. D. C," p. 29, PL 3, Fig. 49). 

 — In a sample of the deposit obtained recently, several examples of 

 what appears to be this form have occurred. Diam. -006". 



C. oblongus, Grev. (" T. M. S.," Vol. xiv, p. 4, PI. 1, Fig. 9).— 

 One specimen has been observed by F. Kitton, Esq., in this deposit, 



Terpsinoe americana, Bail., forma trijona (Pantocsek, " Hung. 

 Diat.," PI. 6, Fig. 53). — A form very similar has been found by 

 Mr. F. Marshall. 



