A V I C U L A. 



Plate V. 



Species 7. (Fig. 7 and n, Mus. Cuming.) 

 AvicuLA FLABELLUM. Avic. tesid oblique siiborbiculari, 

 postice late subsinuatd, pellucido-corned, sqmmis lan- 

 ceolatis fragiliss'mis concentrice longitudinaliter ra- 

 diatd, pallide olivaced, piirpHreo-nigricante irregula- 

 ritiir radiaUm tinctd. 

 The fan Avicula. Shell obliquely suborbicular, slightly 

 broadly sinuated posteriorly, transparent horny, con- 

 centrically and longitudinally rayed with extremely 

 fragile spear-like scales, pale olive, irregularly radi- 

 ately smeared with purple-black. 

 Hub. Venezuela. 



The characteristic sculpture of this species, which is of 

 a comparatively fragile horny texture, consists of a mass 

 of more fragile lanceolate scales, arranged for the most 

 part with tolerable regularity. The shell is more or less 

 radiately smeared with purple-black. 



Species 9. (Mus. Cuming.) 



Avicula barbata. Avic. testa orbiculari, supeme redd, 

 plano-convexd, olivaceo-Jlamcante, concentrice lami- 

 natd, versus marginem dense squamatis, squamis plano- 

 coclilemiformibus, regulariter seqnentibtis. 



The bearded Avicula. Shell orbicular, straight at the 

 upper part, flatly convex, olive-yellow, concentrically 

 laminated, densely scaled towards the margin, scales 

 Hatly spoon-shaped, following regularly. 



Hab. Panama (under stones at low water) ; Cuming. 



Distinguished from A. Cumingii by the regular sequence 

 of the scales, which, so far as we have observed, are only 

 developed near the margin, and by its yellower tone of 

 colour. The species is also fi-om a different locality, and 

 possesses a distinct uniformity of character throughout. 



March, 1857. 



