22 THE * CONCHOLOGISTS = EXCHANGE. 
ON THE GENERIC NAME OF A RE- 
MARKABLE BIVALVE SHELL 
FOUND IN THE CONGO. 
BY C.F. ANCEY. 
In the “ Bulletins de la Societé Malacolo- 
gique de France” for 1886, Dr. A. Trémeau 
de Rochebrune proposed the generic name of 
Chelidonura for the curious species of Iridinidee 
described by Dr. Ed. von Martens, under the 
name of Iridina (Mutela) hirundo, from speci- 
mens collected by Mr. Mechow in the Quango, 
a stream tributary to the Congo. Subsequently, 
a second ‘species was found in the last named 
river and described by Dr. de Rochebrune, 
who then proposed for these shells, which are 
certainly different from any genus of Iridinide, 
the said name of Chelidonura. Unfortunately 
Chelidonura has already been used by M. 
Adams for a shell of the family Bullide, and 
Chelidonura, Rochebrune (non Adams), must 
therefore be changed to Chelidonopsis, Ancey. 
The genus Burtonia, Bourg. (1883) proposed 
for different species of Lake Tanganyika, Cen- 
tral Africa, is certainly nearer to Chelidonopsis 
than any other section it Iridinidz, but they 
want the dorsal carina and the very curious 
appendage of the posterior edge of the valves. 
The true Mutela are quite different in shape. 
The analogy of several species inhabiting the 
countries and streams of West Africa and Lake 
Tanganyika, is not to be wondered at, for the 
latter belongs to the basin of the Atlantic and 
not of the Indian Ocean, and being (during 
part of the year), connected with some of the 
headwaters of the Congo. 
Berrouaghia, Algeria, June 11, 1887. 
DESCRIPTION OF NEW GENERA 
OR SUB-GENERA OF HELICIDA. 
BY C. F. ANCEY. 
(Continued. ) 
XXII —Brazieria, Anc. 
“Testa fere staturce Helicis constrictce, Bou- 
«<bée, lentiformis depressa, imperforata, stria- 
‘« tula, solidiuscula, flavido-corneola; Spira valde 
“‘ depressa, vix convexa. Anfractus 5 planulati, 
‘“sutura lineari divisi; ultimus supra depressus 
“et acute angulatus, infra multo magis convex- 
“jor, turgidus. Apertura obliqua, angulata, 
‘‘Junata, infra convexa, substricta. Peristoma 
“intus labiato incrassatum, margines lamina 
| “elevata juncti.” 
Type: Helix velata, Hombron et Jacy. 
Geogr. distrib.: Caroline Islands. 
This peculiar type of Naninidce possesses am- 
biguous characters, and the typical species was 
placed by Pease, in Trochomorpha, a genus 
which it appears to me not to belong to. 
XXIII.—Chalepotaxis, Anc. 
“Testa characteribus anatomicis peculiarilus 
“a Cl. Gredler in diagnosi Nanince (?) infantilis 
“enumeratis preedita. Testa umbilicata, albido- 
“hyalina, fascia unica ultimi anfractus cincta. 
‘«« Spira convexo-conica, apice obtusa; anfractus 
‘‘regulariter crescentes; ultimus major, rotun- 
“datus, subtus convexus, antice non deflexus; 
“apertura haud labiata; peristoma simplex, 
“ acutum, sinuatum.” 
Type: Nanina (?) infantilis, Gredler. 
Geog. distrib.: Central China: Tonkin. 
XXIV.— Oligospira, Anc. 
“Testa ejusdem insuloe Acayos commemorans, 
“a quibus ultimo anfractus valde tumido, am- 
“bitu oblongo et rotundato et anfractibus cce- 
“teris multo minus numerosis, celerius crescen- 
‘‘tibus et spira depressa, vix elevata nec conica 
“‘discrepat. Anfr. ultimus antice perdeflexus.” 
‘ Types: H: Waltoni, Reeve; H. Skinneri, 
Reeve. 
Geog. distrib. : Ceylon. 
XXV.—Crystallopsis, Anc. 
“Testa inter Papuinas et Geotrochos,—et 
“Corasias quasi media, tenuis, alabastrina vel 
“hyalina, vel fasciis opacis cincta, umbilicata, 
“ olobosa, tenuis, glabra, angulata vel filocincta. 
“Spira convexa, vel conyexo-conica, obtusa ; 
“ anfractus minus numerosi; ultimus maximus, 
