AVICULA. 



Plate XVIII. 



Species 72. (Fig. 68, Mus. Brit.) 

 AvicuLA viTEEA. Avic. testd oliUque curvatd, subspathu- 

 latd, aid late smiiatd, teiiid ; pellucido-albd ; param 

 conwxd, plano-gquamatd, sguamis fere obsohtk. 

 The glassy avicula. Shell obliquely curved, some- 

 what spathulate, with the win;^ broadly sinuated, 

 thill ; transparent-white ; but little convex, flatly 

 scaled, scales almost obsolete. 

 Hab. West Indies. 



Flat and transparent, of thin PlacmiaAWt substance, 

 obliquely spathulate, with a few scarcely-developed fes- 

 tooned scales. 



Species 73. (Fig. 69, Mus. Brit.) 



Avicula Atlantica. Avic. testd oblique ovatd, solidi- 

 usculd, convexd, aid sublaie simiatd, laviffatd; purpureo- 

 fuscd, fasciis angustis pallidis rudiatd, fasciis maculis 

 fuscis ctispid-atis vittatis. 



The Atlantic Avicula. Shell obliquely ovate, rather 

 solid, convex, wing rather broadly sinuated, smooth ; 

 jjurple-brown, rayed with light narrow bands, bands 

 filleted with brown arrow-headed spots. 



Lamauck, Anira. sans vert. vol. vii. p. 98. 

 Mytilm amcula seu Mr undo, Chemnitz. 



Hai. Australia; Jukes. 

 This species has doubtless a wide range of habitation. 



Us most distinguishing characteristic is the rayed pattern 



of narrow light bands, filleted with brown arrow-headed 



marks. 



Species 74. (Fig. 70, Mus. Brit.) 



Avicula reticulata. Avic. testd trigono-ovatd, aid la- 

 tiusculd ; intense purpureo-castaned ; temte concentrice 

 striatd, epidermide minute reticulatd profe marginem 

 indutd. 



The keticulated Avicula. Shell triangularly ovate, 

 with the wing rather broad ; dark rich purple-chest- 

 nut ; finely concentrically striated, covered near the 

 margin with minutely reticulated epidermis. 



Hab. Australia. 



Allied to A. lata, but rather different in form, and of 



darker colour. The epidermis presents a most exquisite 



example of finely tufted network. 



Species 75. (Fig. 71, Mus. Brit.) 

 Avicula Savignyi. Avic. testd oblique oblongd, trigond, 



aid late simiatd ; intense purpureo-nigrd, striis eleva- 



tis concentricis reticulatim indutd. 

 Savigny's Avicula. Shell obliquely oblong, triangular, 



with the wing broadly sinuated ; dark purple-black, 



covered with a couceutric network of raised stria;. 

 Deshayes, Anim. sans vert. vol. vii. p. 102. 



Avicula heteroplera, Sowerby, in Genera of Shells. 



Mytilus morio ; Dillwyn. 

 Hab. Pulo Condore ; Mus. Brit. 



A fine purple-black species, with a broad, expanded, 

 not elongated, wing, beautifully sculptured with fine con- 

 centric stria;. 



June, 1857. 



