AVICULA. 



Plate XL 



Species 36. (Mus. Cuming.) 



AvicuL.\ ZEBK.4. jivic. testa perobli que trapezoidea, sii- 

 penii lata, recta, posfice vix simiala, medio elonyato- 

 convexa, Ifemgatd, peUiicido-cornett, llneis nigricante- 

 fiims didaidibM promiscne vmjaid. 

 The zebra Avicula. Shell very obliquely trapezoid, 

 broad and straight at the uj)per part, posteriorly 

 scarcely sinuated, elonpiately convex in the middle, 

 smooth, transparent horny, promiscuously striped 

 with distant black-brown lines. 

 Ihih. Jloreton Bay, Australia. 



This little Avicula, of which three specimens are exhi- 

 bited in the accompanying figure, attached by their byssus 

 to a bunch of Sertnlari/e, is of a peculiarly oblique form 

 and bright transparent horny substance, promiscuously 

 striped with distant black-brown lines. 



Species 37. (Mus. Cuming.) 

 Avicula flammata. Avic. tenia oblique quadratd, siib- 



depressd, superne angustd, pellucido-corned, fiammia 



rvfo-fmcis fasciatim radiald. 

 The flamed Avicula. Shell obliquely square, rather 



depressed, narrow at the upper part, transparent 



horny, rayed with bands of red-brown flames. 

 Hah. Philippine Islands ; Cuming. 



A small transparent horny species, of somewhat rude 

 oblique growth, rayed with bands of red-brown (lames, 

 and having a delicate tortcise-shell aspect. 



Species 38. (Mus. Cuming.) 

 Avicula scalpta. Avic. testa oblique quadratd, supernii 

 angudiusculd, convexd ; pallide pellucido-corned, liiwis 

 capillaribus opaco-albis, promincue divergentibm, ra- 

 dial d. 

 The scratched Avicula. Shell obliquely square, ra- 

 ther narrow at the upper part, convex ; pale trans- 

 parent horny, rayed with opake-white hair-lines, pro- 

 miscuously diverging. 

 Ilah. Australia. 



A rather convex shell, of a pale, horny texture, curi- 

 ously marked with opake-white hair-lines, promiscuouslv 

 divergi 



■oft-. 



Species 39. (Mus. Cuming.) 



Avicula Pernoides. Avic. testa oblique circulari, sn- 

 periie subanyu.std, pland, solidiusculd, rugosd, mitticd, 

 ad marginem irregulariler crenatd ; lutescente-albd, 

 purpureo-nigro radiald et compicue marmoratd. 



The Pekna-like Avicula. Shell obliquely circular, ra- 

 ther narrow at the upper part, flat, rather solid, 

 rough, without external sculpture, irregularly notched 

 at the margin; yellowish-white, rayed and conspicu- 

 ously mottled with purple-black. 



IM. L ? 



The most noticeable feature in this species is its bold, 

 purple-black marbled painting, which is particularly con- 

 spicuous in the marginal interior. 



Species 40. (Mus. Cuming.) 



Avicula assula. Avic. tesld aubquadrato-ovata, solidi- 

 usculd, poslice subsinuatd, prope umbones obsolete la- 

 minald, deinde squamis lanceolatis fragilibus fimbria- 

 tim obsitd ; subcori/ed, purpureo-rufo radiald et mar- 

 moratd. 



The slab Avicula. Shell somewhat squarely ovate, ra- 

 ther solid, slightly sinuated posteriorly, obsoletely 

 laminated near the umboes, then beset with festoons 

 of fragile lanceolate scales ; somewhat homy, rayed 

 and mottled with purple-red. 



Hab. West Indies. 



A simple stout horny sIicU, rayed and mottled with 



purple-red, densely beset towards the margin with festoons 



of fragile lanceolate scales. 



Species 41. (Mus. Cuming.) 

 Avicula Chamoides. Avic. tesld subquadrato-circulari, 

 tenni, corned, concentriee laminatd, laminis plus minus 

 ampliter ramosis ,- olivaced, undato-nigro maculatd. 

 The Chama-like Avicula. Shell somewhat squarely 

 circular, thin, horny, concentrically laminated, la- 

 miuic more or less largely branched ; olive, blotched 

 with waved black. 



Hah. ? 



A pretty horny species, of which a cluster of four spe- 

 cimens is represented within a valve of .'/. margaritifera, 

 remarkable for the bold Charaa-like branching out of the 

 eoncentric laminse. 



March, 1857. 



