Dr. P. P. Carpenter on new Forms of Mollusks. 311 
XXXII.—Diagnoses of new Forms of Mollusks collected at Cape 
St. Lucas by Mr. J. Xantus. By Puruie P. Carpenter, 
BA, Ph.D. 
THE specimens here described belong to the Museum of the 
Smithsonian Institution, Washington, D.C. The first available 
duplicates will be found in the British Museum or in the 
Cumingian Collection. An account of the labours of Mr. Xantus 
will appear in the forthcoming volume of British Association 
Reports ; and detailed notes on the species may be consulted in 
the American scientific periodicals for the current year. 
Genus ASTHENOTHAERUS*. 
Testa extus “ Thracie”’ similis: intus cardine edentulo, haud 
spathulato ; cartilagine infra umbones sita. 
1. Asthenotherus villosior. 
A, testa ineequivalvi, inzequilaterali, umbonibus ad trientem lon- 
gitudinis sitis ; tenuissima, alba, (sub lente) omnino minutissime 
et creberrime pustulosa ; rugis incrementi obtusissimis, irregulari- 
bus, maxime t. juniore, ornata; epidermide tenui, pallide olivacea 
induta ; parte postica truncata, parum hiante ; antica valde rotun- 
data; marginibus dorsalibus et ventrali parum excurvatis; um- 
bonibus angustissimis; regionibus lunulari et nymphali subcari- 
natis: intus, margine cardinali utriusque valvee acuto; ligamento 
inconspicuo ; cartilagine subspongiosa, satis elongata, postice de- 
flecta; fovea haud indentata; cicatricibus adductorum parvis, 
subrotundatis; sinu pallii majore, ovali, ad dimidium interspatii 
porrecto. Long. °38, lat. °26, alt. +14 poll. 
2. Solemya valvulus. 
S. testa minore, tenuissima, diaphana, vix testacea, cornea, pallidiore, 
lineis tenuibus, distantibus, fuscis, radiatim ornata; postice tenui- 
ter radiatim striata; tumente, satis elongata, marginibus antico et 
postico regulariter excurvatis; umbonibus vix conspicuis ; lineis 
anticis divaricantibus, extus parentibus, intus lacunam cartila- 
gineam definientibus; cardine edentulo; ligamento postice elon- 
gato, antice curto, latiore, bifurcato; cicatricibus adductorum 
subrotundatis. Long. °85, lat. °25, alt. +14 poll. 
3. Tellina (Peroneoderma) ochracea. 
T. testa majore, parum ineequilaterali, tenui, satis planata; carneo- 
ochracea, intus intensiore; levi, nitida, marginem versus striis 
~ imcrementi; postice vix radiatim striatula; ventraliter antice 
valde excurvata, postice vix angulata; marginibus dorsalibus ob- 
* AaGevis, weak; Oarpos, hinge. ’ 
t+ The measures of length are taken from the anterior to the posterior 
margins. 
