300 Mr. A. Adams on new Molluscafrom Japan. 



new forms were occasionally met with. I enclose, with a 

 request that you will be so good as to insert them in your 

 Journal, descriptions of those among the Mollusca which were 

 the most interesting, and am, Gentlemen, 



Your obedient servant, 



Arthur Adams. 



Genus Constantia, A. Adams. 

 Testa acuminato-ovalis, rlmata, spira elata, attenuata ; anfractibus 

 rotundatis, ultimo ventricoso, plicis tenuibus longitudinalibus et 

 livis elevatis transversis decussatis. Apertura ovalis, longior quam 

 lata ; peritremate libero, continuo, niargine integro, acute. 

 This genus, I believe, belongs to the natural family Scalida, 

 although the whorls are not disunited or ribbed ; the aperture, 

 moreover, is oblong, and the texture of the shell very thin. 



Constantia elegans, A. Adams. 

 C. testa tenui, rimata, acuminato-ovali, pallide fusca ; anfractibus sex, 

 tribus supremis Itevibus simplicibus, anfractibus alteris plicis tenui- 

 bus longitudinalibus et lirulis transversis reticulatis ; apertura ob- 

 longa, peritremate continuo, margine libero, acute. 

 Hab. Straits of Korea, near Mino-Sima ; dredged from 63 

 fathoms. 



Genus Idle, A. Adams. 

 Testa turrito-subulata, umbilicata ; anfractibus convexiuscuhs, traus- 

 versim sulcatis, sulcis subdistantibus, interstitiis lengitudinaliter 

 cencinne striatis. Apertura oblonga, postice acuminata, antice 

 Integra, rotundata ; labie libero, simplici, acute. 

 This genus is founded upon a deep-water shell, of which, un- 

 fortunately, I possess but a single specimen. It most nearly 

 resembles a perforate, elongated, sulcate Odostomia, without any 

 tooth or fold on the inner lip. 



I am unable to refer it to any genus, and consequently give 

 it generic rank myself. The practice of throwing a doubtful 

 form into any genus seems to me to retard the progress of 

 science, — shirking a difficulty, and confusing the mind of the 

 student. The number of genera is of no more moment to the 

 naturalist than the number of species, provided they each re- 

 present a particular type of form. The natural position o( lole 

 is, perhaps, between Monoptyyma and Menestho. 



lole scitula, A. Adams. 



I. testa sulndato-turrita, profunde umbilicata, alba, selidluscula ; an- 

 fractibus sex, convexiusculis, trausversini sulcatis, sulcis subdi- 

 stantibus, interstitiis lengitudinaliter cencinne striatis ; apertura 

 oblenga, antice rotundata, postice acuminata; labie simplici; labro 

 margine acute. 



Hah. Straits of Korea ; dredged from C3 fathoms. 



I 



