M D I L A. 



Plate IX. 



Species 49. (Fig. 62, Mus. Cuming.) 

 MoDioi.A NIGRA. Mod. testa subquadrato-omtd, com- 

 jiresuiuculd, aniice dense tenuiitriata, medio leevigatd, 

 poslice ad extremitateiri liratd; purpureo-nigrd. 

 The black Modiola. Shell somewhat squarely ovate, 

 rather compressed, anteriorly densely finely striated, 

 smooth in the middle, posteriorly ridged at the extre- 

 mity; purple-black. 

 Hanley, Brit. Marine Couch., Eecent Bivalve Shells, 



p. 242. 

 Lanisliua nigra, Gray, Conch. Syst. pi. 100. f. 3. 

 Hab. Orsund Bay, Sweden. 



A rather compressed species, of deep purple-black co- 

 lour, belonging, together M'ith the rest of the species in 

 this Plate, to the genus Modiolarca, CretieUa, and Lank- 

 Una of authors. 



Species 50. (Fig. 63, a, 6, Mus. Cuming.) 



Modiola Cumingiana. Mod. testd oblongo-ctmeiformi, 

 curimld, ienuiculd, aniice valde gibbosd, tumidd, temd- 

 siriatd, obtuse angulatd, medio lavigatd, postice ad 

 extremitatem obscure liratd; fulvescenle-cortied, rufes- 

 cente-fiisco interdum nndatd. 



Cuming's Modiola. Shell oblong wedge-shaped, curved, 

 rather thin, very gibbous and swollen anteriorly, fine- 

 ly striated and obtusely angled, smooth in the middle, 

 posteriorly obscurely ridged at the extremity ; ful- 

 vous-horny, sometimes waved with reddish-brown. 



DuNKER, MS. Mus. Cumiug. 



Ilab. Moreton Bay, .Australia. 



An extremely delicate species, of a characteristic swollen 



wedge-shape. 



Species 51. (Fig. 64, Mus. Cuming.) 



Modiola i.mpacta. Mod. testd ovato-eimeiformi, tumidd, 

 postice et antice radiatim liratd, liris angustis, sitbre- 

 motis, ittrinque excavatis, medio lavigatd; intense oli- 

 mced, corned, nitente. 



The driven Modiola. Shell ovately wedge-shaped, 

 swollen, posteriorly and anteriorly ridged, ridges 

 narrow, rather distant, excavated on both sides, 

 smooth in the middle ; dark-olive, horny, shining. 



Herman, Naturforscher, vol. xvii. pi. 3. f. 5-8. 



Mytilus cor, Marty n. 



Mytilus discors, Lamarck (not of Linnreus). 



Hab. New Zealand (in sponge). 



This, the finest species in the group, is not, as shown 



by M. Deshayes, the Liunean Mytilus discors. It is 



larger and more gibbous, j)carly and purple-rayed within. 



Chemnitz gives a characteristic figure of the species 

 vol. viii. pi. S6. f 768. 



Species 52. (Fig. 65, JIus. Cuming.) 



Modiola discors. Mod. testd oblongd, subciineiformi, 

 tumidd, antice radiatim liratd, liris tenuibus, subob- 

 scuris, liris posticis fortioribus, remotis, medio lavi- 

 gatd; olivaeed, corned, nitente. 



The differing Modiola. Shell oblong, somewhat 

 wedge-shaped, swollen, anteriorly radiately ridged, 

 ridges fine, rather obscure, posterior ridges stronger 

 and more distant, middle smooth ; olive, horny, 

 shining. 



Mytilus discors, Linnseus, Syst. Nat. p. 1159. 

 Mytilus discrepans, Lamarck. 



Hab. Massachusetts (found adhering to seaweed) ; Gould. 

 The anterior stria; in this species are fine and close-set. 



Species 53. (Fig. 66, Mus. Cuming.) 

 Modiola laevigata. Mod. testd oblongo-ovatd, antice 

 latiore, subcompressd, undigue concentrice striata, me- 

 dio subexcavatd, extremitate posticd obscure sulcata; 

 olivaceo-castaned, corned, nitente. 

 The smooth Modiola. Shell oblong-ovate, broader an- 

 teriorly, rather compressed, everywhere concentrically 

 striated, slightly excavated in the middle, posterior 

 extremity obscurely grooved ; olive-chestnut, horny, 

 shining. 

 Lanistina lavigata. Gray. 

 Hab. Greenland. 



The peculiarity of this species consists chiefly in the an- 

 terior area not being longitudinally ridged. 



Species 54. (Fig. 67, Mus. Cuming.) 



JMoDioLA nexa. Mod. testd oblongo-ovatd, convexo-com- 

 pressd, antice parum latiore, undique dense lineari-sul- 

 calls et liratis, liris medianis siibtilissimis, fere obso- 

 ktis ; castaneo-fnscd, mnbonibus plus minus ero-tis, 

 margaritaceis. 



The tied Modiola. Shell oblong-ovate, convexly com- 

 pressed, anteriorly but little broader, everywhere 

 densely linearly grooved and ridged, middle ridges 

 very fine, almost obsolete ; chestnut-brown, umboes 

 more or less eroded, pearly. 



Gould, Invert. Massachusetts. 



Hab. Massachusetts Bay ; United States. 



A rather compressed red -brown species, in which the 



])osterior and anterior portions are sculptur(;d alike with 

 1 densely-set stria;. 



December, 1857. 



