UNIVALVES. 



PLATE XIV. 



Genus. SEPTA. 

 Character. Shell spiral ; the spire and body intersected by membranaceous septse 

 or divisions, placed irregularly and alternately on the body and spire ; the first of 

 these forms the maxilla oris, the rest are placed upon the body and spire ; the beak 

 variously bent. The septse are of a different colour from the rest of the shell. 



Species. 



No. 1. Septa parkinsonia. Shell olive-coloured, and angulated ; the mouth white, 

 with a tuberculated edge, inclining to gray. This shell being hitherto un- 

 described, I have taken the liberty of naming it Parkinsonia, in honour 

 of Mr. James Parkinson, of Hoxton, author of a curious Work upon the 

 natural history of fossils. It is a native of the coast of New Holland. 



No. 2. Septa scarlatina. Shell variegated with scarlet, yellow, and white 

 streaks ; spire round and blunted ; the mouth narrow and small. A native 

 of Amboyna and the Eastern Seas. 



No. 3. Septa spengleri. Shell brown, sometimes covered with a green epi- 

 dermis ; spire tuberculated ; mouth deeply ridged, and white. A native of 

 New Holland. 



No. 4. Septa rubicunda. Shell red, beautifully streaked with white and brown 

 marks ; spire tuberculated ; the mouth denticulated, and having two white 

 teeth on the inner side. This shell resembles the Murex tritonia of Lin- 

 naeus ; but is much smaller. It is a native of New Holland. 



No. 5. Septa rubecula. Shell variegated, brown, red, and white ; the mouth 

 having a rounded channel at the top, like the rest of the Septse, only more 

 distinctly marked. This shell is a native of the South Seas, and has been 

 mistakenly called a Murex by some authors who have delineated and de- 

 scribed it. 



No. 6. Septa triangularis. Shell reddish brown, variegated with white and 

 dark brown marks; its singularly angulated form, and particularly its 

 angular cheek, will easily distinguish it from the rest of its congeners. It 

 is a native of the Southern Ocean. 



REMARKS. 



The various forms of this curious genus are very striking, and sometimes apparently oppo- 

 site to each other ; nevertheless, if we take the following character as our guide, namely, 

 membranaceous folds, longitudinally placed, one of these forming the cheek of the mouth 

 and the rest of the folds irregularly placed, all the difficulty of classing them will cease at 

 once. At the same time it will be found that these shells have a natural relation to each 

 other in many more respects, such as the folds being painted generally of a different colour 

 from the rest of the shell, the indented notch, and tooth faintly marked at the top of the 

 mouth. This general relationship will fully justify the accurate Conchologist in separating 

 them from the Murex and all other genera hitherto described. 



