21(1 ATTRIA, DISCITES. 



cles were extended radiall}^ from the head, somewhat like those 

 of a sea anemone ; but each pair had its definite and ditferent 

 direction, which was constantly maintained ; thus one pair of 

 tentacles was held pointing directly downwards, two other pairs, 

 situate just before and behind the eyes, were held projecting 

 obliquely outwards and forwards, und backwards respectively, as 

 if to protect the organs of sight.* 



N. STENOMPHALUS, Sowb. PI. 99, fig. oO'.l. 



Shell like K. FompiJii's. but very narroAvly umbilicated. 



Eastern ArcMpelago. 



I scarcely think this deserves to be separated from N. Pom- 

 piliua : tlie very narrow umbilicus is exposed simply because the 

 callous deposit has not spread sufficiently to cover it ; there is 

 no excavation around the umbilical region, as in the following 

 species. 



X. MACROMPiiALUs, Sowb. 1*1. 99, fig. .MO. 



Umbilical region excavated, butwitli rounded margin ; umbili- 

 cus wide, exi)Osing the whorls. 



Nero Caledonia, etc. 

 X. UMBiLK'ATi s, Lister. PI. 99. fig. oil. 



Surface smooth to spirally striate; umbilical region wide, 

 :in<iularly excavated, umlnlicus wide, showing all the whorls. 



Solomon Islands, New Ireland, etc. 

 The strise are not constant ; I have therefore reunited with 

 this species N. scrobiculatus of Dillwyn and Gould und N. per- 

 foratuii., Conrad. 



Subgenus Aturia, Bronn. 



Sutures of septa with a deep lateral lobe ; siphuncle on the 

 concave or inner side of the shell, large, continuous, like a suc- 

 cession of funnels. 



Four species. Eocene. N. America ; Uurojje ; India. 

 A. ziczAC, Sby. PI. 98, figs. .502, 503 o.. Eocene. BritUh. 



Subgenus Discites, McCoy. 



Whorls all exposed ; last chamber sometimes produced. 

 Five species. L. Silurian — Oarb. 



* Mosely, Notes by a Naturalist on the Challenger, 296. 



