STRUCTURE AND HISTORY ОЕ PLAV. 275 
(the natural river embankment), are narrow strips which extend for many 
miles along the water-courses (see Map, Pl. 25), but others, such as Letei and 
Caraorman, are more or less fan-shaped (only a few of the existing grinds 
are shown on the maps). Some grinds, Letei and Caraorman for example, 
are never flooded, others are flooded annually, and others again are exposed 
only when the river is very low. Some are not known by name, whereas 
Letei and Caraorman possess several distinct villages, are cultivated and 
covered in places by sparse natural forest (see Appendix E, p. 283). The soils 
forming the grinds are river-, sea- and wind-borne, and mostly recent. Some, 
however, are composed of upland soil, loess, as the grindu Chiliei, for 
example, which is steppe like much of the country surrounding the delta, 
having been cut off from the upland by the river. The loess grinds corre- 
spond to the holmes of the Norfolk Broads district, river islets of upland 
soil (glacial loams, sands and clays). The grinds can roughly be classified 
as follows :— 
(1) Grinds of river-deposited soils, the grindul Malului for example. 
(2) Grinds of sea-drifted material, of which numerous examples exist 
between Lake Razim and the village of St. George. These are low, narrow 
sand-banks running parallel to the coast-line. Some of them are almost 
entirely composed of shells, in the main of whole shells near the sea, and of 
broken shells further inland. The present beach consists almost entirely 
of shells and is in some places, as for ‘instance near Portita [Portitsa |, cut 
back straight down by the waves. In such places the stratification into 
narrow bands of coarse and fine shells respectively is well shown. 
The most abundant beach-forming shells are Cardium edule, Linn., and 
Corbulomya mediterranea, Costa; and Mytilus edulis, Linn., and Nassa reti- 
culata, Deshayes, are also common. In places where freshwater streamlets 
issue from the Balta, dead shells of Planorbis corneus, Linn., and Viripara 
vivipara, Se., are abundant. Balanus improvisus, Darwin, is very often 
attached to Corbulomya *. 
With these marine-formed grinds, long narrow and shallow salt lagoons, 
called Zatons, often alternate. The sea still continues to give rise both to 
new grinds and to new Zatons. For instance, in front of the Zatons marked 
Vechiu (old) and Nou (new) on Dr. Antipa’s map, а fresh Zaton somewhat 
to the south-west of Zatonul Nou is to be looked for in the near future. 
The sea does not break on the beach there, but on a sand-bank—the future 
grind—still covered by water and indicated by the wreck of a small boat as 
well as by the line of breakers ; between this underwater bank and the 
present beach lies the Zaton of the future. 
(3) Grinds formed of wind-blown sand. These grinds are practically 
all composite in character as regards soil. They are certainly formed in 
* Таш indebted to Mr. J. С. Robson, of the British Museum (Natural History), for kindly 
naming the Mollusca. 
