94 THE NAUTILUS. 



Pt. violacea. Indian O., Zanzibar. 



The last species is certainly quite distinct, but the other two minor 

 groups are of slight value, the apertural wrinkles being a dynamical 

 feature incipient in lumbis itself. 



Group F {Harpago.) 



Here the antesinual lobe gives rise to one of the great claivs, a fea- 

 ture unique among living Strombs, and sundering it widely from the 

 previous group, from which Dr. Gill long ago divorced it. 



H. chiragra, rugosa. 



Distr. : Zanzibar to .Japan and Polynesia. 



The six groups previously considered agree in the strong and heavy 

 shells, usually of large size, with spreading callus. Those which fol- 

 low are usually rather small and of lighter structure, and have the 

 inner lip restricted or defined. 



Group G {Gall inula). 



Shell usually light, elegant ; antesinual lobe diminished, lip ex- 

 panded medially, descending rapidly from the suture with a broad 

 sinuation ; posterior canal narrow, hugging the spire ; body somewhat 

 flattened in front of the aperture, usually with four or five sagittate 

 color bands; the early whorls with small varicose ribs at intervals. 



Contents as given by Tryon, with the probable addition of S. pul- 

 chellus, which is unknown to me autoptically. 



Distribution : Red Sea and Zanzibar to Japan and Polynesia. 



S. canarium, isabella. 



Red Sea to Japan and Australia. 



The last two species, erroneously grouped with the American forms 

 by Tryon, but correctly placed by Chenu and others, are aberrant in 

 their heavier' growth, obscure posterior canal and undefined inner lip. 

 These differences, however, hardly seem to warrant the institution 

 of a sub-group. 



Group H {Conomurex). 



Shell conoid, often distorted ; lip with margin rather straight and 

 incurled, posterior sinus deep, anterior sinus distinct, oblique, remote 

 from the canal ; inner lip narrow, scarcely defined ; color bands 

 sagittate. 



S. luhuanus, mauritianus, fasciatus, gibberulus. 



Distribution: Red Sea and Natal to Japan and Polynesia. 



