114 MRS. E. M. EEID ON TWO [vol. lxxvi, 



on either side of the crest; at the hase these channels expand, 

 ■and form two well-marked pits. 



Length=3 mm. ; breadth = 2 - l mm. 



There is considerable resemblance in size and general shape 

 between this species and the last, but a close examination shows 

 the distinctive characters of each as described. 



I have not been able to identify the species. 



From Tegelen, British species only were recorded ; from the 

 Reuverian 10 species were described, none of them British. I have 

 ■a fairly complete collection of British species, but can find nothing 

 to resemble these two. It is probable that they are exotic. 



NAIADACE^:. 



Naias minor Allioni. 



A small fragment of the base of a seed was found. It was quite 

 •characteristic, showing very clearly the ladder-like sculpture. It 

 was however very small, being smaller than any other specimen of 

 the species that I have seen. Unfortunately, this minute specimen 

 decayed before it was possible to photograph it. 



Naias minor, as well as AT. major, occurred in the greatest 

 abundance in the Teglian and Cromerian. It did not occur in the 

 Reuverian, though several extinct species were recorded. At Castle 

 Eden this minute fragment is the sole representative of the genus. 

 Its present-day distribution is veiy Avide, extending throughout 

 Central Europe, the Mediterranean region, Central Asia, China 

 and Japan, and tropical Africa. 



ALISMACE^E. 



Alisma Plantago Linnaeus (var. ?). (PL YIL, fig. 7.) 



Achenes narroAv, oval, almost oblong ; narrow cuneiform in 

 section ; style apical. 



Length=l"8 mm. ; breadth = - 75 mm. 



These achenes are rather narrow and thick, and have a subapical 

 ■style. In the living A. Phtutago the style is usually near the 

 middle of the ventral margin, but occasionally it is as in the fossil. 

 Although the character appears fairly constant in the few nuts 

 found at Castle Eden, for the reason that I have been able to 

 match them from recent specimens, I do not like to separate them 

 as a variety. Tegelen specimens have the same style as those from 

 Castle Eden, but are broader, and resemble more closely the average 

 achenes of the living species. Cromerian specimens have a ventral 

 style. 



The present distribution is throughout the northern temperate 

 regions and Australia. 



