Report on the zoological collections made in the Indo-Pacific Ocean ...

MOLLtrsCA. 41ridge, and between this and the first lira and in the intersticesbetween the other lir;x) the surface is finely striated. The lastwhorl is elongate, has about thirty-one ridges in addition to theminute infcerstriation. The aperture is narrow, contracted anteriorlyinto a short, broadish canal, together equalling almost halfthe total length of the shell. The columella is perpendicular,curving a little to the left in front, and coated with a very tliincallosity. The labrum is thickened exteriorly, arcuate in the middle,faintly sinuatcd towards the lower extremity, and rather deeplynotched in the slight constriction of the whorl near but not at thesuture.Length 15 millim., diam, of last whorl above the mouth 4g ;aperture 7 long, 2 wide.Hah. Arafura Sea, N". Australia, 32-36 fms.This species is peculiar on account of the absence of longitudinalcosta?. The outer lip is smooth in the single specimen at hand, butin other and more mature shells it might be more or less dentatewithin.10, Cythara cylindrica, var, (Plate IV. figs. H-H 1.)Mangelia cylindrica, JReeve, Conch. Icon. sp. 9.Var.=M. lyrica, Reeve, I. c. sp. 30.Hah. Port Curtis, 7 fms, {Coppinger) ;Philippine Islands{C^^m^ng\This species differs from the typical Ci/tharce in having no transverselirpe on the columella, in this respect agreeing with C. hornheckii,Reeve, C. turricula, E,eeve, and G. vitiensis, Smith.The variety (C. lyrica) is a trifle larger than the normal form,and the riblets are rather stronger at the upper termination. Withthese feeble distinctions the differences end. In both forms aminute tubercle is sometimes, but not always, met with upon theupper part of the columella, and about fifteen fine lira3 may becounted within the exteriorly thickened labrum, which is shaUowlysinuated near the suture, and prominently arcuated when viewedlaterally. The longitudinal costse number about fourteen on thepenultimate whorl, and the principal transverse thread-like lirajabout eight, but upon the last volution there are as many as twentysix.The entire surface is beautifully cancellated with minuteraised lines of growth and microscopic spiral lira;, a feature seenonly in well-preserved shells and under a powerful lens. Thesculptured whorls are six in number, the remaining two apical onesbeing smooth and glassy.The single specimen, in beautifnl condition, from Port Curtis,presents certain differences which it may be as well to mention.At the upper part the whorls exhibit a faint concavity a littlebeneath the suture, of which I perceive a trace in the type of thespecies, but not in the variety (C. lyrica), and the cost?e are rathermore numerous, there being about 17 upon the penultimate whorl,