58 M.O.A.L.MORCH’S REVIEW OF THE VERMETID2. {Feb. 1], 
3. BrvontIA SUBTRIQUETRA, Morch. 
T. valida, lateraliter affixa, irregulariter torta ; anfr. primi litui- 
formes vel planorbiformes ; carina mediana elevata, compres- 
siuscula; latere externo planiusculo, subperpendiculari, basi ex- 
panso, liris plerumque destituto; latere interno convexiuseulo 
(in junioribus plano), liris 10-12 e@quidistantibus ; strie incre- 
menti leviter sigmoidee ; dissepimenta interna tenuia, convexa, 
Diam. aperturee circ. 12m. 
Var. a. SQUAMIFERA. 
_ 1. carina dorsali parum prominente, squamis paucis remotis com- 
 ~ pressis acutis ; latere interno liris 4—5 validis angustis sub- 
squamosis, interstitiis lirulis 1-2 inequalibus ; latere externo 
superne lirulis 2-3. 
Diam. aperture cire. 7 m. 
? Favanne, La Conchyl. pl. 66. f. B 2, fem. juvenile? 
Fossilis in form, tertiaria ad Asti (coll. T. O. Semper). 
This species has the same relation to B. triquetra as Thylacodes 
melitensis, Gm., to T. intiotiosa, Salis. 
4. Brvonta suTitis, Morch. 
T. affixa irregulariter lituiformis, fere libera; anfr. graciles, primi 
irregulariter planorboidet, carnei, liris expressis longitudinali- 
bus alternatim minoribus, submoniliferis, interstitiis granulis 
validis, remotis, sepe cum lateralibus confluentibus, inde serobt- 
culis elongato-quadratis reticulata ; sculptura aperturam versus 
levior vel fere evanescens ; anfr. ultimus solutus, longus, albe- 
scens, varicibus duabus majoribus et duabus minoribus. 
Diam. aperture et anfr. ult. cire. 3 m. 
Hab. In littore occidentali Americze centralis, in valva solitaria 
Veneris subimbricate Sow. affixa (Mus. Cuming). 
This species is exceedingly like to Bivonia semisurrecta, Biv., but 
differs chiefly in the catenulated granulations of the furrows and 
moniliferous appearance of the lirz. 
Var. a, ? MAsOR, Liris 3-4 validioribus, ubique impresso-punctata, 
Diam. aperturee 7 m. (coll, Dunkeri, 222). 
This specimen, on a fragment of a Pinna, probably from Central 
America, is very like a large variety of B. semisurrecta in the Mu- 
seum of Breslau. 
Var, 8. TRIQUETRA. 
T. corrodens, irregulariter planorbiformis, triquetra, lira dorsali 
distincta; ruge et strie incrementi utrinque siymoidee ; lire 
longitudinales obsoletissim@ vel evanescentes. 
Diam. aperture 5 m. 
Hab. Mazatlan, on a valve of a Placunanomia (Semper’s collection 
at Altona). 
I cannot see any notable difference between var. § and Bivonia 
