A V I C U L A. 



Species 18. (Mus. Cuming.) 

 AvicULA HYSTiiix. Avic. testa suhglobosd, ienui, corned, 

 virescente, paUide radiald, spinis vitt(eformibus eloii- 

 gatis, promiscue curvatis, e Imninibus tennibus projectis, 

 induid. 

 The porcupine Avicula. Shell subglobose, thin, horny, 

 green, faintly rayed, covered with long ribbon-like 

 spines, promiscuously curved, projected from fine 

 laminae. 



Hab. ? 



This little species of thin globular form is distinguished 

 from all other species of the genus by its long promiscu- 

 ously curved ribbon-like spines. 



Species 19. (Mus. Cuming.) 

 AvicuLA RUTILA. Acic. testa ohlique siibqiiadratd, tenui, 



IcBvigatd, pellncidd, aneo-rufescente. 

 The ruddy Avicula. Shell obliquely subquadrate, thin, 



smooth, transparent, coppery -red. 

 Hab. .-Vustralia ; Strange. 



Of very simple structure, being of a thin transparent 

 coppery-red substance, somewhat rudely developed, with 

 out any indication of scales or over-lapping laminae. 



Species ii. (Mus. Cuming.) 



Avicula pulchella. Avic. testa peroblique ovatd, su- 

 perne awjmtiore, convexiusculd, teniiissmd, pellueido- 

 corned, Jiamniid'is rufis angustis radiatd,m.aculis nigris 

 linels stibtilibits opaco-albis commistis. 



The pretty Avicula. Shell very obliquely ovate, nar- 

 rower at the upper part, rather convex, very thin, 

 transparent horny, rayed with narrow red flames, in- 

 termixed with black blotches and fine opake-white 

 lines. 



Hub. riiilipplnc Islands ; Cuming. 



An exceedingly transparent shell, curiously painted 

 with interrupted rays of black spots, narrow red flames 

 and fine opake-vvhile lines. The shell is of very oblique 

 growth, and broader at the base than at the upper part. 



Species 20. (Mus. Cuming.) 



Avicula perviuidis. Avic. testd oblique ovatd, convexi- 

 usculd, superne late alatd, corned, perviridi, paUide 

 radiatd, squamis paucis eximiis mucronatis prope 

 margvnem. 



The green Avicula. Shell obliquely ovate, rather con- 

 vex, broadly winged at the upper part, horny, bright 

 green, faintly rayed, with a few delicate pointed scales 

 near the margin. 



llab. Australia ; Strange. 



Of an unusually bright-green horny substance, faintly 



rayed, with a few flattened pointed scales in the rays near 



the margin. 



Fig. 21. (Mus. Cuming.) 

 The young state of the large Avicula margaritifcra, de- 

 scribed and figured at PI. I. 



Species 23. (Mus. Cuming.) 



Avicula radula. Avic. testa subquadratd, planiusculd, 

 irregulari, circa iimbones lavigatd, deinde squamulis 

 acvdis fimbriatis appressis armatd, albd, luteo-tinctd. 



The rasp Avicula. Shell somewhat square, rather ap- 

 pressed, irregular, smooth around the umboes, then 

 armed with flat pointed frilled scales, white, tinged 

 with yellow. 



Hab. '■: 



A yellow-stained opake-white shell, of rude irregular 



growth, beset with appressed sharp-pointed frilled scales. 



Species 24. (Mus. Cuming.) 



Avicula occa. Avic. testd oblique ovatd, convexiusculd, 

 preesertim valm dextrd, corned, solidimculd, olivaced, 

 nigra interrupte radiald, conspicue squamatd, squamis 

 planis, crispatis, mannoratis. 



The harrow Avicula. Shell obliquely ovate, rather 

 convex, especially the right valve, horny, rather solid, 

 olive, rayed with interrupted black, conspicuously 

 scaled, scales flat, crisp, mottled. 



Uab. lied Sea. 



Allied to A. ala-perdicis, from which it differs chiefly in 



the scales being larger and more regularly festooned. 



March, 1857. 



