34 HULL SCIENTIFIC AND FIELD NATURALISTS' CLUB. 



Channel was again excavated to carry off the Winestead 

 drainage water, and a clough erected near the Humber (1868). 

 At present, the former course of the Haven is marked by a 

 shallow depression with a series of pools from one to three 

 feet wide and about four inches deep. After over half a mile 

 of this, it drops about a dozen feet into the Winestead drain, 

 and this enters the Humber by a modern clough (1868), a 

 mile and a half away. The pools are brackish ; the mud in 

 them is black, with no sign of the yellow Humber silt; and 

 thev are above the level of all except the highest spring tides. 

 They contain Paludestrina ventrosa, and a few Spfueroma 

 rugicauda, but no P. stagnalis, nor the other Crustacea found 

 in tidal pools. On the sides, amongst a luxuriant growth of 

 Triglochin niaritimum and Plantago maritima, Alexia occurs 

 in profusion, sometimes crawling up the stems of the plants 

 like a Sticcinea: the shells are larger and thinner than those 

 found on the Humber bank. Thus we have here a mollusc 

 which usually requires a periodic bath of salt water, living in 

 a situation where the salt water can never reach it, for there 

 seems no reason for supposing that the tidal water has flooded 

 this area since the erection of the clough. Its normal posi- 

 tion on the Humber bank is at the roots of grass, &c, at 

 high water mark of average tides ; I have not taken it above 

 the level of a 26 ft. tide (Albert Dock). It occurs again 

 inland on the sides of a closed ditch on Cherry Cob Sands. 

 Here it was accompanied August 1902), by Paludestrina 

 ventrosa, P. stagnalis^ Pakemonetes varians, Spfueroma rugi- 

 cauda, and Idotea marina ; and from the presence of Idotea 

 and P. stagnalis I suspect that the ditch has been connected 

 with the Cherry Cob Sands drain till recently. All the 

 specimens of P. varians from this locality are marked with 

 red dots, and have only one tooth on the lower edge of the 

 rostrum. 



This ditch, and the immediate neighbourhood of the 

 clough in Cherry Cob Sands drain, form the only inland 

 localities so far discovered in Holderness for Paludestrina 

 stagnalis. On the foreshore it occurs in abundance from 

 Spurn to Wehvick, and thence in decreasing numbers to 

 within a few miles of Hull, and it shares the brackish pools 

 at Easington (seashore) and Saltend, which are out of the 

 reach of ordinary tides, with P. ventrosa. The latter inhabits 

 all the brackish ditches inland, but has not been found on 

 the foreshore. P. jenkinsi is only known as a freshwater 

 shell in Holderness. 



All the brackish water Crustacea mentioned above may be 



