PEE EN A: 
Puate I. 
Testa marina bivalvis, binusculosa, latere postico plus 
minusve radiatim flecuoso vel angulato; dentes 
cardinales divergentes ; dentes laterales plerumque 
obsoleti: impressio pallit 
Ligamentum externum. 
validi, nonnunquam 
maximt, sinuata. 
Shell-marine, bivalve, binuscular, with posterior side 
more or less radiately flexuous or angular; car- 
dinal teeth divergent; lateral teeth generally 
strong, sometimes obsolete; palleal impression 
with a very large sinus. Ligament external. 
As this work is intended for the discrimination of 
species rather than of genera, the collector will no 
doubt tind included in this monograph a number of 
forms which might be more conveniently separated 
into genera such as have been adopted by modern 
authors. But if we have found it difficult to name an 
assemblage of characters exclusively and inclusively 
descriptive of the forms here assembled, we should find 
it little less difficult, in dividing the groups into 
smaller genera to define the single characters by which 
to distinguish them. Thus the presence or absence of 
lateral teeth would seem to be a good distinction, were 
it not that in some species these teeth exist only in one 
valve, in others in one side, and in others are so nearly 
obsolete that it is difficult to say whether they exist or 
not. So with the posterior flexure, which disappears 
by infinitesimal degrees as the observer passes from 
species to species. 
There are few genera of Mollusca whose geographi- 
cal distribution is so wide as in the genus before us. 
From high northern regions to the south of Australia 
and New Zealand, from extreme Hast to extreme West, 
wherever conchological fauna of any extent exist, 
there will a good proportion of Telline be found 
among them. A great number of the larger species 
are collected in the West Indies, and many of great 
beauty are natives of the Philippine Island coasts. 
Perhaps nearly a fourth of all the species are supplied 
from these two series of localities, the remainder being 
pretty equally distributed. 

Species 1. (Mus. Sowerby.) 
TELLINA Fausta. Tel. 
solidd, subventricosd, albida, concentricé subundu- 
testa orbiculari-subtrigond, 


umbones obsoletis ; 
latere postico subtrigond, leviter flecuoso, subobsolete 
Margine ventrali rotundatim acelivi, 
margine dorsale recti, declivi, termino truncato ; 
latim striata, striis versus 
angulato, 
ligamento magno, prominente ; latere antico rotun- 
dato, margine dorsali declivi, umbonibus subacume- 
natis. 
PROSPEROUS 'TELLINA. 
nal, solid, subventricose, whitish, with concentric 
shghtly undulating strie, which are obsolete to- 
wards the umboes; posterior side subtrigonal, 
slightly flexuous, with a nearly obsolete angle, 
ventral margin roundly sloped, dorsal margin 
straight, sloped, truncated at the end; ligament 
large, prominent; anterior side rounded, dorsal 
THE Shell orbicular-subtrigo- 
margin sloped, with umboes rather acuminated. 
Donovan, vol. iii. t. 98, Dorset Cat., t. 5. f. 5. 
Tellina levis, Wood. 
Tellina remies, Bom. 
Hab. West Indies. 
The young specimens of this species are smooth, and 
often golden tinted. 

Fig. 2, Species 18. 
Tetiuina MapaGascariensis. <A view of the right valve 
is given in Plate V. species 18, under which num- 
ber it is described. 

Fig. 3, Species 20. 
TeLLina RuFEscens. The right-hand valve, which is 
considerably the deeper, is figured in Plate V., 
Species 20, under which number it is described. 

Species 4. (Mus. Sowerby.) 
Tretia piscus. Tel. testd solidissimd, suborbicularis, 
inequivalvi, subequilaterali, ventricosd, albida, 
concentricé striis undulatis rugata, prope wmbones 
levigatd, striis tenuissimis radiata, rugis concen- 
tricis prope marginem ventralem et ad latera pro- 
fundis, rudibus ; valvuld dextra profundiori, ad 
marginem ventralem alteram superanti ; latere 
postico prope marginem ventralem angulatim im- 
April, 1869. 
