1891.] THE 'challenger' expedition. 441 



15. ScALARiA DisTiNCTA. (Plate XXXV. fig. 15.) 



Testa elongata, gracilis, alba ; anfractus perconvexi, lente accres- 

 centes, costis tenuibus circiter 1 6 (Jiie illic una crassiore) paulo 

 obliquis histructi, liris spiralibus tenuioribus circa 5 supra 

 castas continuis ornafi ; anfr. idtimiis medio carinatus, infra 

 concavus, sublcevis ; apertura subcircularis. 



Longit. 11 millim., diam. 3|; apertura 2| longa et lata. 



The larger costae are about twice as thick as the rest, and one in 

 number on every whorl. 



16. Odostomia (Turbonilla) fischeri. (Plate XXXV. 

 fig. 16.) 



Testa gracilis, subulata, alba, polita ; anfractus normales 9, convexi, 

 lente crescent es, sutura subprofunda sejuncti, longitudinaliter 

 confertim plicati, plicis in anfr. tdtimo infra medium obsoletis ; 

 apex sinistrorsus, globosus, Jieliciformis ; apertura parva, longit. 

 totius |- adcequans ; columella subperpendicularis, vix arcuata, 

 anguste reflexa, haudplicata vel contorta. 



Longit. 9 millim., lat. 2| ; apertura 2 longa, Ij lata. 



Of the two specimens under examination, one has the costas rather 

 more decidedly developed than the other. The latter exhibits slight 

 traces of spiral striae below the suture. 



17. Odostomia (Turbonilla) coNSANGuiNEA. (Plate XXXV. 

 fig. 17.) 



Testa O fischeri simi7is, sed gracilior, anfractibus normalibus 11 

 constructa, costis latioribus 14-15 parum elevatis ornata ; aper- 

 tura parva, longit. totius ^ — ^ adcequans. 

 Longit. 10 millim., diam. 2; apertura fere 1| longa, 1 lata. 

 The ribs or plicae in O. fischeri are about seventeen or eighteen in 

 number and considerably finer than in the present species. Besides 

 this distinction, the proportions with regard to length are so different 

 that there is little doubt that they constitute separate species. 



18. Odostomia (Turbonilla) constricta. (Plate XXXV. 

 fig. 18.) 



Testa elongata, parum pyramidalis, cclba, nitida ; anfractus nor- 

 males octo, subplani, sed, in medio leviter constricti, sutura linearis 

 distincta sejuncti, costis rectis 16—17 interstitia subcequantibtis, 

 instructi, anfr. ultimus inferne Icevis, ad peripheriam rotunda- 

 tus ; apex globosus, sinistrorsus, Icevis; apertura plus minus 

 subquadrata, longit. totius -^ suhoequans ; columella leviter 

 obliqua, haucl torta. 



Longit. 5J millim., diam. 1| ; apertura 1 longa, | lata. 



The constriction is just a trifle above the middle of the whorls, 

 which have a slightly turreted appearance. 



19. Solarium atkinsoni. (Plate XXXV. figs. 19-19 b.) 

 Testa discoidalis, acute carinata, mediocriter umbilicata, albida, 



swperne depresse conoidalis, lateribus leviter convexis, infra 



