20 



POST-TERTIARY ENTOMOSTRACA. 



5. Laminated clay (estuarine or marine), as a rule, only containing a few Fora- 

 minifera. 



6. Unfossiliferous Boulder Clay. 



An instance in which the fossiliferous clay has been found between two Boulder 

 Clays has been already noted. 



We examined in detail the following section at Short Road Brickwork (south side of 



road). 



1. Mould . . . . . . 3 to 4 ft. 



2. Gravel (no fossils) . . . . • i upwards to 1 ft. 



3. Thick dark clay (fossihferous, especially in the lower 0 ft.) 13 ft. 



4. Laminated whitish clay (with Foraminifera) . . 1^ ft. 



5. Yellowish-brown clay (with Foraminifei'a) . . 2 ft. 



6. Muddy sand, not cut through (Foraminifera and Ostracoda). 



The Boulder Clay is met with at about the same level in a pit not more than 100 

 yards distant, and without doubt forms here, as tliroughout the district, the base of the 

 series. The first seven feet under the gravel is brownish coloured, especially towards 

 the top, and contains comparatively few fossils. Among these Mytilus modiolus is found 

 with united valves. The next six feet run into a dark- grey clay with an abundant 

 fauna. In the tenth and eleventh feet below the gravel is a bed of Cyprina Islandica. 



The layer of laminated whitish clay (4) under this is more sharply defined below 

 than above. When dry it has little cohesion and breaks down easily between the fingers 

 like a piece of chalk. It is finely laminated, and washes almost wholly away through a 

 sieve of ninety-six meshes to the linear inch. In washing 100 oz. of dry clay, only two 

 drachms were left as a residue, which consisted of very fine sand and a considerable number 

 of Polystomella striato-punctata and Nonionina depressula. 



The yellowish-brown clay (5), constituting the next two feet in the section, is much 

 more cohesive ; the layers are divided from an inch to half an inch apart by fine sand ; and 

 these again into excessively thin layers by lighter and darker coloured clays. In washing, 

 this is similar to the clay above it, and only one Foraminifer was met with. The muddy 

 sand (6) underlying this loses 63 per cent, in washing ; but the greater part of the loss 

 is an extremely fine sand. Three Foraminifera were met with, and one valve of Cytheridea 

 punctillata. 



The fossils in the clay beds around Paisley are mostly confined, as in the section we 

 have now described, to the lower half of the deposit, and generally have their chief 

 abundance within from one to three feet of the laminated clay. 



Foraminifera and Ostracoda are met with, more or less, from top to bottom of the 

 clay, more constantly Foraminifera ; but as a rule both are found most profusely where 

 Mollusca prevail. In many cases Mytilus edulis occurs in considerable abundance below 



