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Show 1891.] THE'CHALLENGER' EXPEDITION. 439 8. PLEUROTOMA (DRILLIA) CROSSEI. (Plate XXXIV. fig. 8.) Testa parva, breviter fusiformis, albida; anfract. 7, supremus Icevis, convexus, cceteri superne leviter concavi, rotunde angulati, infra angulum arcuatim contracti, costis obliquis tenuibus circiter 15 (in anfr. idt. inferne attenuatis) instructi, line-isque elevatis paucis parum conspicuis infra angulum ornati ; anfr. ult. inferne vcdde contractus ; apertura parva, longit. totius •| adcequans ; labrum supra angulum hand prof uncle sinuatum. Longit. 10 millim., diam. 3|; apertura 4 longa, 2 lata. This species has tbe whorls much contracted at the lower part and prominent at the rounded angle. The riblets are oblique below, and flexuous in the concavity. The spiral lirae are more conspicuous around the lower part of the body-whorl than elsewhere, and altogether absent in the concavitv below the sutural line. 9. PLEUROTOMA (DRILLIA) HOYLEI. (Plate XXXIV. fig. 9.) Testa parva, breviter fusiformis, albida; anfract. 8, superne oblique concavi, in medio obtuse angulati, infra angulum contracti, vix convexiusculi, costis oblique flexuosis, prcecipue angulum (supra et infra mox evanidis) instructi, striisque incrementi tenuissimis sculpti; apertura parva, longit. totius pernio superans; sinus labri mediocriter profundus, in con-cavitate situs. Longit. 9 millim., diam. 3| ; apertura, 3 | longa, 1| lata. The costae in this species are very short, and soon become obsolete above and below the angle, so that they appear like a series of oblique nodules. The absence of spiral sculpture is peculiar. 10. PLEUROTOMA (DRILLIA) WATSONI. (Plate XXXIV. fig. 10.) Testa parva, breviter fusiformis, cdba; anfr. 6, supremi duo (nucleus) Iceves, convexi, cceteri superne oblique declives, angulati, infra angulum plani, costis tenuissimis obliquis circiter 20 lirisque spiralibus (in anfr. superioribus duo, ultimo circiter 14) nodose cancellati, sujira angulum liris spiralibus paucis subobsoletis cincti; anfr. ult. infra medium valde contractus; sinus mediocriter profundus; labrum arcuatum, prominens. Longit. 6| millim., diam. 3g ,• apertura 2-| longa, 11 lata. This shell has a large smooth apex ; the upper slope of the whorls is comparatively smooth, exhibiting only a few (about 4) faint spiral lirae, and the lower portion and the greater part of the body-whorl are covered with a distinct cancellation, the points of intersection of the oblique and transverse lirse being rather acutely nodulose. 11. CANCELLARIA EXIGUA. (Plate XXXIV. fig. 11.) Testa minima, elongata, ovata, cdba; anfract. 4-5, supremus (nucleus) magnus, Icevis, globosus, cceteri convexi, circa medium liris duobus spiralibus cincti, costis obliquis tenuibus circiter |
