LITHODOMUS.— Plate 1. 



gradually attenuated, equal in the anterior, dorsal 



margin rather convex, not angled. 

 Modiola gracilis, Philippi, Zeitschrift fur Malac. 1847; 



Abbildungen, pi. 2. f. 1. 

 Hab. China. 



This fine species, the largest of the genus, is of a rich 

 dark chestnut colour, with the furrowed sculpture of the 

 anterior surface somewhat delicately indicated. 



Species 5. (Fig. a, b, Mus. Cuming.) 



LiTHODOMUS CINNAMOMINUS. LHhod. Ustd cj/Undraceo 

 cuneiformi, tumidd, sviarcuatd, undiqiie minuiissimi 

 decmsatim striata, cmtaned aid Jlavescenle-castatied, 

 niiente, quasi sericea, extremitate anticd abrupte Irun 

 caid, umionHms nilide involutis, posited subcompressd. 



The cinnamon Lithodomus. Shell cylindrically wedge 

 shaped, swollen, rather arched, everywhere very mi 

 nutely decussately striated, chestnut or yellowish 

 chestnut, shining as though silky, anterior extremity 

 abruptly truncated, vvith the umboes neatly involuted, 

 posterior extremity rather compressed. 



Mytilus ciriiiayiiominus, Chemnitz, Conch. Cab. vol. viii. p. 

 352. pi. 82. f. 731. 



A/i/titm cmriamomem, Bruguiere. 



Modiola cinnumonuia, Lamarck. 



Hau. Philippine Islands, and Island of St. Thomas, West 

 Indies. 

 This species is peculiarly distinguished by its swollen, 

 wedge-shaped, ModiolaASkt form, and shining, silky ap- 

 pearance. 



Species 6. (Mus. Cuming.) 

 Lithodomus obesus. Llthod. testa oblongd, medio obesd, 

 utrinque fere cequaliter rotundatd,Jlavescente; Itevi anl 

 concentrice striatd, margine ventraii arcuato, dorsali 

 declivi-angulato, angulo fere obsoleto, extremitate un- 

 tied stibattmuatd, umbonibus indistinctis. 

 The stout Lithodomus. Shell oblong, stout in the 

 middle, almost equally rounded at both ends, yel- 

 lowish, smooth or concentrically striated, ventral 

 margin arched, dorsal slopingly angled, with the angle 

 nearly obsolete, anterior extremity rather attenuated, 

 umboes distinct. 

 Modiola obesa, Philippi, Zeitschrift fiir Malac. 1847 ; Ab- 

 bildungen, pi. 2. f. 2. 

 Hab. China. 



Well distinguished by its stout, nii>;iilni- form, and ab- 

 sence of furrowed sculpture. 



