270 DR. P. P, CARPENTER ON NEW SPECIES [Mar. 14, 
Genus CycLADELLA. 
Testa bivalvis, tenuis, equilateralis, equivalvis, haud hians, um- 
bonibus planatis. Ligamentum tenuissimum, externum. Cardo 
linea curvata, dent. lat. distantibus, card. transversis, haud 
radiantibus. 
56. CYCLADELLA PAPYRACEA, 0. Sp. 
C. t. tenuissima, subdiaphana, epidermide tenui induta, planata, 
suborbiculari; concentrice fortiter lirata, liris rotundatis, intus 
excavatis; tota superficie lineis granulosis radiantibus creber- 
rimis minutissime celata; dent. card. ii. transversis, mar- 
gin dorsali subparallelis ; dent. lat. validis. 
=“ Tellina ?eburnea, Hanl.” (fragments only), Maz. Cat. no. 56. 
Mr. Hanley kindly sent for my inspection a perfect pair (as 
“‘ Lepton” ), which he had found nestling in a burrow in Spondylus. 
The hinge more resembles Cyclas (Lam.) than any other known 
genus. Its great peculiarity is, that the cardinal teeth, instead of 
radiating from the umbo, fall in the curve of the hinge-line, as 
though uniting the lateral teeth. The shell is too thin (being deeply 
indented within by the concentric waves) to make out the pallial 
line ; but no trace of sinus is visible. It may therefore rank, provi- 
sionally, under Kelliade, although in other respects its affinities 
appear to be with (dalia and Cooperella. The ligament appears 
little more than a prolongation of the epidermis. Beside the trans- 
verse cardinal teeth, there is in each valve a curved line, slightly 
raised, like the end of a finger-nail, which bounds what would be the 
lunule in other shells. 
Long. *1, lat. +123, alt. -045. 
Hab. Mazatlan; one perfect specimen from Havre Collection 
(Mus. Hanl.) ; fragments, Liverpool Collection. 
706. ? MonTACUTA OBTUSA, Nn. Sp. 
2M. ¢. planata, valde inequilaterali, subrhomboidea ; subdia- 
phana seu chalcedonica, haud punctata, levi ; marginibus ple- 
rumque regulariter excurvatis, dorsali recto, umbonibus haud 
prominentibus ; cardine, utraque in valva, dente uno cardinal 
et fossa ligamentali ; dent. lat. altera valva elongatis, rectis, 
altera vix conspicuis. 
Differs from ? M. dionea in the elongation of the lateral teeth, 
and in the possession of a distinct cardinal tooth in each valve. 
Long. *047, lat. -06, alt. -01. 
Hab. Mazatlan ; two fresh specimens, Liverpool Collection. 
Tablet 2530 contains the larger specimen; the other is trans- 
parent. 
696. PecruncuLus, sp. ind. 
Tablet 2531 contains a minute valve, ‘033 across; outside with 
close, prominent concentric ridges, foliated by about twenty-four 
