NUCULA. 15 



short. Anterior extremity rounded. Antero-dorsal margin slightly curved. 

 Postero-dorsal margin short, nearly straight. Ventral margin gently curved. 

 Measurements : 



Length . . . . .7 mm. 



Height ..... 5'5 ,, 

 Thickness ..... 3-25 „ 

 Remarks. — There are a few specimens of this small species in the British 

 Museum and one or two in Mr. Meyer's Collection. One in the British Museum 

 was figured by Gardner as N. simplex, Deshayes, but it seems to me to be distinct 

 from that form — it is smaller, much more triangular, and has a smaller apical 

 angle. Until a larger series of specimens has been obtained I do not feel 

 justified in giving this form a distinctive name. 



Distribution. — Lower Greensand of Atherfield and Shanklin. 



Nucula Meyeri, Gardner, 1884. Plate II, figs. 21 a — c. 



1884. Nucula Meyeri, /. S. Gardner. Quart. Journ. Geol. Soc, vol. xl, p. 130, 



pi. v, figs. 14 — 16. 



Remarks. — This form is at present very imperfectly known. It is small, 

 triangular, and high ; with lines of growth, and a large lunule. Gardner states 

 that "it is most nearly allied to N. impressa of Blackdown," but it seems to be 

 almost indistinguishable from N. antiquata, Sowerby. 



Measurements : 



(i) (2) 



Length . 8 - 5 . 85 mm. 



Height . .8 . 7 



1 is the type specimen ; 2 is from Redcliff. 



Types. — In the British Museum. 



Distribution. — Lower Greensand of Atherfield ; Perna-bed of Redcliff. 



