1927] | Pulsbry-Bequaert, The Aquatic Mollusks of the Belgian Congo 455 
since many of these stations happened to be below or above places where 
banks of Htherza were common, because here falls or rapids interrupted 
transportation. , 
‘The process of transforming these shells into lime is rather simple. 
A circular hole, serving as a primitive lime kiln, is dug in the ground. 
Its walls are lined with logs about six feet in length, and a quantity of 
firewood is placed at the bottom. The shells, after being thoroughly 
washed and dried again, are shoveled in to form a layer about a foot 
thick. More firewood is piled on, then another layer of shells, and finally 
the whole kiln is covered over with firewood. The photograph (PI. 
XLVII) shows at the left a kiln burned out, with the calcined shells 
scattered around, and at the right another kiln about to be filled with a 
heap of dry shells (Htherza elleptica) lying nearby.” (H. L.). 
Driessenidze a 
The shell is mytiliform with anterior, nearly or quite terminal beaks, and without 
a nacreous layer within. Thereis a small septum (myophore of the anterior adductor) 
across the beak cavity. The ligament is immersed. The posterior adductor scar is 
very long. 3 | 
The mantle margins are concrescent, leaving only the siphonal and small pedal 
openings. Byssiferous. 
Congeria Partsch 
Congeria Partscu, 1836, Ann. Wiener Mus. Naturg., I, p.97. Type by designa- 
tion of Pilsbry (1911, The Nautilus, XXV, p. 95): Congeria subglobosa Partsch. 
Enocephalus v. MiinstEr, 1831, Zeitschr. f. Geogn., Geol. u. Naturg. ‘Erde, X 
Stiick, p. 92, without definition or described type.!. Partscu, 1836, Ann. Wiener Mus. 
Naturg., I, p. 97, as identical with Congeria. 
Mytilopsis ConRAD, 1857, Proc. Ac. Nat. Sci. Philadelphia, IX, p. 167. Mono- 
type: M. leucophzatus Conrad. | 
Praxis H. anp A. Apams, 1857, ‘Gen. Recent Moll.,’ II, p. 522. Type by present 
designation: Dreissena africana Van Beneden. 
Mytiloides Conrad, 1874, Proc. Ac. Nat. Sci. Philadelphia, XX VI, p. 29. Not 
Mytiloides Brongniart, 1822. For Dresseina scripta Conrad and D. leucophxata 
Conrad.. Error for Mytilopsis Conrad. 
1Graf von Miinster, in a letter dated December 26, 1830, published in the following year, writes of 
certain Austrian mytiloid fossils, concluding: ‘‘In der v. Schlottheimschen Sammlung befindet sie sich 
unter dem Namen Enocephalus, daher ich sie in meiner Sammlung aufgefiihrt habe, als Hnocephalus 
carditeformis von Wien, und mytiloides vom Plattensee.”’ 
The same fossils had been mentioned by Boué (1830, Journ. de Géol., II, pp. 374 and 378 as a “ My- 
tilus d’eau douce, voisin de celui du Danube,’’ but without name or description. Later (1833, Bull. Soe. 
Géol. France, III, séance du 21 janvier, p. 126), Boué mentioned “deux ou peut-étre trois espéces de 
Mytilus ou d’un nouveau genre intermédiaire entre les Isocardes et les Moules, appellé Hnocephalus (E. 
carditxformis, etc., par le comte Minster).’”’” There is no description or figure. 
No clue to the identity of Enocephalus was published until the name was mentioned by Partsch as 
identical with his new genus Congeria. Minster’s two species, EZ. carditzformis and mytilordes, have 
never been correlated with any of the described forms, so far as we have been able to learn, though they 
are doubtless identical with species described by Partsch. 
