THE NAUTILUS. 43 



I venture to give tins varietal name to the shell I have mistaken 

 for the true H. singularis Pfr. (see Nautilus, 1897, p. 27), which 

 is described from Aneitum. According to !Mr. Sykes (loc. supra cit., 

 p. 197), specimens of the latter, so named by Dr. Pfeiffer, are in the 

 British Museum, and are the ordinary, large, strongly-keeled form 

 usually met with in collection. The present one is also strongly but 

 obtusely angled, has 6 whorls only and the last whorl is not deflected 

 at all in front. It is 6^ mm. high and 6 mm. wide. In size it is 

 quite like D. Walkeri Sykes (loc. supra cit., p. 197, fig. II), but the 

 latter appears to have a higher body-whorl and more rounded peri- 

 phery. It was collected on Espiritu Santo island, very distant from 

 that of Aneitum. 



5. Dendrotrochus Eva (Pfr.). 

 Hab. Vate island. 



It is peculiar, I think, to the above island. The specimens are 

 more commonly white, sharply keeled, with or without a brown lip. 

 In others the keel is more obtuse, while in some cases there is a 

 brown zone between the keel and the suture. 



6. Dendrotrochus Layardi (Hartm.). 



Hab. Aura (= Aurora island), fide Layard ; also Espiritu Santo 

 island (J. J. Walker, Dr. Ph. Francois). 



I have seen an extensive series of this fine shell, originally de- 

 scribed as "Oxychona." It is now well established that Oxychona is a 

 genus of Bidimulidce allied to Zaplageus and DrymcEiis, restricted in 

 its distribution to Brazil. The present species is related to D. Eva, 

 which it appears to replace in the northern group. The following 

 variations occurred to my notice : 



a. Plain ashy-white. 



b. Ornamented with a narrow brown line on the keel and the 

 suture. 



r. With a wide dark-brown band between the keel and the sutures, 

 sometimes extending, sometimes fading on the upper whorls. 



The lip is either brown or whitish and the base, around the axis, is 

 frequently tinged with brown. There are always some minute spots 

 and black, oblique lines on the pale ground. 



7. Diphmorpha Brazieri Hartm. 



Hab. Espiritu Santo island. A scarce species, never found, I sup- 

 pose, in fresh condition. 



8. Diphmorpha Delantouri Hartm. 



