MOLLUSC A. 51 



of this species is smoother than that of the preceding, the tentacles being longer and the eyes smaller, 

 placed on slight swellings, not, however, resembling even the rudiments of peduncles. 



Hab. Eastern Seas. 



The operculum of Thorns is horny, soft, and flexible, formed of concentric and radiating 

 fibres. On the under surface it is smooth and attached to the foot by the central part, and free 

 around the circumference and posterior portion. On the upper surface it is covered with 

 radiating ridges, or salient processes formed by the constituent fibres being elevated in 

 succession one above another. 



38. DELPHINULA, Lamarck. 



1. Delphintjla stellaris. PI. XI. Fig. 7. Delph. testa orbiculari-discoidea, spira depresso-plana, 

 subampliter umbilicata, anfractibus superne concavo-angulatis, ad angulum squamato-carinatis, squamis 

 compressis, erectis, infra regulariter squamato-spinosis ; alba, purpurascente sparsim tincta. 



Hab. Eastern Seas, near Basilan. 



This has very much the appearance of an immature shell, although it differs from the 

 young of any of the larger described species. 



39. SCALARIA, Lamarck. 



1. Scalaria maculosa. PI. XL Fig. 14. Seal, testa, elongato-turrita, vix umbilicata, anfractibus 

 decern, rotundatis, lsevibus, politis, costis annularibus subdistantibus, tenuibus, prope suturas latioribus et 

 flexuosis ; cserulescente-alba, fusco promiscue maculata. 



Hab. China Sea. 



The brown spots which characterize this species have a promiscuous blotchy appear- 

 ance, about two between each annular rib. 



2. Scalaria neglecta. PI. XL Fig. 15. Seal, testa conico-turrita, profunde umbilicata, anfractibus 

 septem ad octo, rotundatis, lcevibus, aut, sub lente, minute spiraliter impresso-striatis, costis annularibus 

 subdistantibus, angustis, elevatis, prope suturas spinoso-uncinatis, aperture rotundata, labro chlatato; 

 carneo-fuscescente, costis albis. 



Hab. China Sea. 



The hook-like spine upon the upper part of the ribs is laterally very compressed and 

 bent slightly backwards. 



3. Scalaria eximia. PI. XL Fig. 16. Seal, testa pyramidali-turrita, acute acuminata, haud umbili- 

 cata, anfractibus novem, costis annularibus numerosis, angustis, lamehatis, prope suturas conspicue spi- 

 noso-uncinatis, costarum interstitiis eximie spiraliter liratis ; casrulescente-alba. 



Hab. China Sea. 



The prominent uncinate spine upon each rib gives a beautiful pyramid-like form to 



