1927] _ Pusbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 85 
Yo (R.), see Komadugu Yobe (R.). Zoetendal Valley.—34° 40’ S., 20° E. 
York, East Griqualand. ; Zoutpansberg.—23° 20’ S., 30° 30’ E. 
Zugue, Marungu, Belgian Congo. 
Zasaga, see Zazega. Zwartkop.—33° 50’ S., 25° 30’ E. 
Zazega.—15° 25’ N., 38° 50’ E. Zwellendam, see Swellendam. 
Review oF BIBLIOGRAPHY 
The first fresh-water mollusks reported from the Congo basin were 
obtained a century ago by the ill-fated expedition of Captain J. K. 
Tuckey, who was despatched in 1816 by the British Admiralty to ascend 
the River Congo, or Zaire, from its mouth. The expedition tried in vain 
to overcome the many obstacles to navigation offered by the region of 
the Cataracts, between Matadi and Leopoldville. Pernicious fevers 
decimated the crew and caused the loss of the Commander of the Expedi- 
tion and of its two naturalists, John Cranch and Christian Smith. In an 
appendix to Captain Tuckey’s ‘Narrative’! there is a fragmentary 
account of the invertebrates collected by Cranch. In the ‘Narrative’ 
itself (p. 93), Tuckey mentions for the first time the peculiar fresh-water 
mussels of the genus Hgerza, which are such a characteristic feature of the 
Congo estuary: “A great quantity of shell fish, of the Mya genus, are 
taken out of the mud round Kampenzey island? by the natives; and the 
fish, stuck on wooden skewers, as the French do frogs, and half dried, 
are an object of traffic; their state of half putrefaction being entirely to 
the taste of the Negroes. In a raw state they are uneatable, having no 
flavor of the oyster.’” 
It is probable that some of the shells described by Reeve and Sowerby 
from the Congo, between 1820 and 1870, had been obtained by Tuckey’s 
expedition, for no fresh-water mollusks appear to have been collected 
in our territory during that half-century. Curiously enough, the next 
aquatic mollusks brought back from our territory came from Lake Tan- 
ganyika, giving to the scientific world the first inkling of the remarkable 
fauna of that lake. Richard Burton and J. H. Speke reached its eastern 
shores, February 13, 1858, and the shells which they picked up on the 
beach and brought back to England were described by Woodward in 
1859.4. They included representatives of the typically Tanganyikan 
species Iridina spekit Woodward, Grandidieria burtont (Woodward), 
11818. ‘Narrative of an Expedition to explore the River Zaire, in 1816, under Cartain J. K. 
bers WP stare ue low, sandy islands near Malela, where Mr. Lang and the junior author also 
found the nativ’s Ss aie same ‘ Narrative,’ p. 291. Smith calls the island Sangam 
ees oe ae pp. 348-350, Pl. xivil. 
