225 
In this species the margins of the lozenge er ligamental area are 
acute, and the ligamental fossa is protected on each side by a pro- 
duced lamina ; the lunule is very deep and nearly triangular, and the 
concentric strize on the valves seem to be undulated on account of 
the impressed grooves which radiate from the beaks. - 
17. Lucina uacrea, A. Adams. L. testa crassa, orbiculari, sub- 
ventricosa, lactea, vix obliqua, concentrice lamellosa, lamellis 
distantibus, regularibus, interstitiis striis elevatis, radiantibus, et 
lineis transversis decussatis, umbonibus fere medianis, prominulis ; 
latere antico rotundato, subtruncato, et subangulato; postico 
rotundato ; cardinis dente apicali antico, lato, prominente ; intus 
incrassata alba, margine ventrali crenulato. 
Hab. Swan River (Dr. Bacon) ; New Zealand (Mr. Strange). 
Mus. Cuming. 
A peculiar species, having somewhat the aspect of a Cordis, but 
without any lateral teeth, and with the anterior primary tooth of one 
valve very broad and dilated. 
18. Lucina (Copakra) munpa, A. Adams. L. testa lenticulari, 
convexiuscula, equilaterali, albida, costulis radiantibus, dichotomis, 
ad latera divaricantibus, ornata; concentrice imbricato-striata ; 
umbonibus medianis, minutis, anteversis ; lunula excavata, intus 
lutescente ; margine ventrali radiaiim sulcato ; cardinis dentibus 
apicalibus duobus, divergentibus, lateralibus, validis. 
Hab. Moreton Bay (Mr. Strange). Mus. Cuming. 
A very neatly sculptured species, with dichotomous radiating ribs, 
and with the inner margin of the valves radiately grooved. 
19. Lucina (CRypropon) puicirera, A. Adams. L. testa 
subquadrato-ovali, equilaterali, subcompressa, sordide alba, epi- 
dermide fusca, tenui induta, concentrice plicata, plicis tenuibus, 
distantibus, latere antico margine sinuato, sulco obliquo, ad mar- 
ginem extendente, impresso ; latere postico obtuse angulato, mar- 
gine subtruncato ; lunula elliptica ; cardinis dentibus apicalibus 
nullis, dente laterali antico instructo; intus alba. 
Hab. Borneo. Mus. Cuming. 
This is a plicate species in which the primary teeth appear to be 
obsolete or wanting, and where there is only a single lateral tooth in 
each valve. This belongs to the form to which the name Cryptodon 
has been given. 
20. Luctna (Myrr#a) tayarpi, A. Adams. L. testa lenti- 
culari, solida, convewiuscula, alba, equilaterali, costulis radian- 
tibus, subnodoso-squamosis, ornata, concentrice sulcata, umboni- 
bus minutis, centralibus, latere antico costis imbricato-lamellosis, 
postico superne rectiusculo ; intus candida, margine ventrali crenu- 
lato, intus radiatim sulcato.  . 
Hab. Ceylon (£. L. Layard, Esq.). Mus. Cuming. 
In form and sculpture this aac very much resembles L. (Myr- 
tea) Stranget, but it is much more compressed, and the radiating 
ribs are more nodose than scaly. 
