16iO PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Hydrobia Parkinsoni, n. sp. Pl. II. fig, 21. 



Testa ovato-conica, la;vi ; anfractibus 5 rotundatis, ultimo ventricoso ; apep- 

 tur^ obliqua, ovata ; sutura subprofunda. 



A very small conical shell, with five or six rounded and smooth 

 volutions ; the last volution is somewhat ventricose, with an ovate 

 aperture. 



This species much resembles Pahidina intermedia, Melleville, but 

 that shell is smaller, more obtuse, and the form of the aperture 

 different. 



Common in the Woolwich beds from Guildford to Upnor. Named 

 after Mr. J. Parkinson. 



From Mr. Prestwich's collection. 



Hydrobia Websteri, n. sp. Pl. II. fig. 22. 



This species much resembles the preceding, but is verj' slightly 

 larger, and has a more expanded and rounded mouth, which gives it 

 a more elegant appearance. It is a rarer form, and occurs in the 

 same beds. 



Named, like the preceding species, after a well-known investigator 

 of the geology of our Tertiary districts. 



Paludina LENTA, Sow., var. /3. Mor. Pl. II. fig. 23. 



Testa ovato-conica, laevi ; anfractibus 5-6 subrotundatis ; apice obtuso ; 

 apertura subovata. 



A smooth conical shell, with five or six rounded volutions, the 

 apex obtuse, and the aperture somewhat ovate. This form, which 

 is difficult to distinguish from the P. lenta, Sow., is also considered 

 by M. Deshayes to occur in the Soissons (Lower Eocene) beds, and 

 to be the same as that found in the Isle of Wight. 



Common in the Woolwich beds at Peckham, New Cross, and 

 Counter Hill. 



Notes on the Entomostraca of the Woolwich and Reading 

 Series. By T. Rupert Jones, Esq., F.G.S. 



1. Cytheridea* Mulleri, Miinster, sp. Pl. III. fig. /. Bosquet, 

 Entomostraces fossiles des terrains tertiaires de la France et 

 de la Belgique, p. 39. pl. 2. fig. 4 a-f. 



The valves of individuals of this species have been collected in great 

 number by Mr. Rosser in the Woolwich beds ; both in the shelly 

 clays (of the middle of the series), and in the pebbly sand above the 

 clays. I have also found them in some plenty in clay with remains 

 of oyster shells from Woolwich, and I have met with rare specimens 

 in the "Oyster-bed" at Clay Hill, Shaw, near Newbury. 



Generally the English specimens slightly differ from M. Bosquet's 



t Cytheridea (Bosquet) is a subgenus of Cythere (Miiller), a minute bivalved 

 Crustacean inhabiting salt and brackish waters. 



