SCUTIBRANCHIATA. 41 



M. Moquin Tandon, who is not addicted to di- 

 viding species with too great minuteness, divides 

 these shells into four species, and separates them 

 into two sub-genera ; I have not been able to verify 

 the accuracy of the subdivision. 



1. AuRICELLA. Shell with elevated ridges. Aper- 



ture sinuous, slit obliquely in the front part in 

 a line with the suture. 



A. (Auricella) lineata, t. 38. f . 4 — 7. — Shell red- 

 dish yellow, with distant ridges, whorls rather de- 

 pressed; aperture with a short oblique slit; the 

 peristome sub-continuous. (Auricula lineata. Drap. 

 Hist. t. 3. f. 2021.) The shell is sometimes nearly 

 smooth. 



2. Platyla. Shell smooth, aperture flat, without 



any slit in the upper part. 



A. (platyla) fusca, t. 38. f. 8. 16. — Shell very 

 smooth, reddish yellow; whorls slightly convex, 

 peristome nearly continued. (Turbo fuscus. Walker, 

 T. M. Rar. 112. f. 42. — Aurychium lineatum. 

 Ross. Jun. f. 408.) 



Order II. SCUTIBRANCHIATA. 



Gills consisting of two series of lamellse, forming 

 one or two series over the back of the neck, or 

 under the edge of the mantle round the foot; rec- 

 tum often traversing the heart. Animal herma- 



