228 
appearances a distinct although closely allied species, and accord- 
ingly assigned to it a new name in my MS. At Neufchatel I 
again saw "Tschudi’s analis (the types described in the Fauna Peruana 
being contained in the Museum at that place), and I was also so 
fortunate as to obtain by exchange, through the courtesy of M. Cou- 
lon, ‘the Directeur of the Museum there, a duplicate example of 
that species. Upon comparing this with a skin lately received by 
Mr. Gould along with other birds from the neighbourhood of Quito, 
I find the same differences as I had previously noted in the Berlin 
Museum specimen; and, fortified by a second example, no longer 
hesitate to introduce the bird as new to science under the title of 
Tridornis porphyrocephala. 
2. DescRiIpPTIONS OF (SUPPOSED) New Species AND VARIETIES 
OF SHELLS, FROM THE CALIFORNIAN AND West Mexican 
Coasts, PRINCIPALLY IN THE COLLECTION oF HvuGH 
Cumine, Ese. By Puiuipe P. Carpenter. 
1. PANDORA CLAVICULATA. 
P. t. magna, complanata, alba, epidermide fusca induta ; antice 
curtissima, postice valde rostrata ; rostro lato, valde projiciente, 
sulco in ulraque valva ab umbone currente ; concentrice undulata; 
margine ventrali maxime excurvato ; margine dorsali postico sub- 
irregulariter arcuato ; cardine lira (quasi clavicula) ligamentum 
Serente prelonga, dimidium ab umbone rostrum versus decurrente ; 
dente antico satis producto; valva dextra denticulo tertio inter 
alios munita ; cicatricibus muscularibus, antica rotundata, postica 
ovali, a margine valde distantibus, inter quas punctularum catena ; 
aliter pagina interna haud punctata. 
Long. 1°23, lat. 1°78, alt. *22 poll. 
Hab. Mazatlan : legit ‘‘ Conway Shipley, a olim Lieut. R.N. 
Mus. Cuming. 
This magnificent species differs from seat forms found in the 
Philippines and New Zealand, in having the fold much larger, with 
the dorsal margin less arcuated. In form it closely approximates 
the Californian species, P. punctata, Conr.; but differs in the 
absence of punctures (except at the pallial line), and in the remark- 
able character of the hinge. In P. punctata, the ligament is (in one 
valve) affixed to the outer margin, which is bent upwards to receive 
it at right angles; in this, there is a sharp internal ridge, or clavicle, 
fully one half of the entire length from the umbo to the beak, at the 
base of which the ligament is situated. 
2. Lyonsta (OsTEODESMA) DIAPHANA. 
L. t. valde inequilaterali, irregulari, sed plerumque pyriformi ; al- 
bida, tenuissima, translucida; epidermide nitida,albo-fusca induta ; 
parte antica parba, satis excurvata; parte postica maxime pro- 
longata, margine dorsali incurvato ; margine ventrali excurvato, 
