[8a 



from the 4' keel, the innermost borders the umbilicus; these spirals are narrow, cordlike, 

 with large interspao d by riblets in very various direction. Umbilicus rather large, but 



nearly closed by the columellar margin, leaving only ;i fissure. Aperture incomplete, a rather 

 id but not deep fissure at the upper part, rounded and turncd up behind; shape of aperture 

 subquadrangular, irregular by the terminations of the keels, columellar margin expanded towards 

 the left, formed by a deep, rounded sinus above and another narrower one below, with a 

 strong tooth between them, this tooth is strongly compressed, as if formed by pinching the 

 columellar margin, 



Alt. 5. lat. apert. alt. i 1 /.,, lat. I 8 / 4 Mill. 



This es resembles, in shape var. lincata Wals. of S. monocingulata (Watson's Journ. 



Lin. Soc. Lond. Vol, 14. p-587; u Challenger"-Gastropoda, p. 106, PI. 7, fig. 1); but the general 

 outline is more convex and the elaborate sculpture is quite different, so I don't hesitate to 

 describe it as new. 



5. Seguenzia sp. 



Stat. 300. io°4S'.6S., I23°23'. 1 E. Timor Sea. 918 M. Fine, grey mud. 1 Spec. 



From this Station a specimen has been collected, belonging to the rimatc species, it 

 differs from the preceding one by its l)roader, less conical shape and its very simple sculpture, 

 consisting, as far as I can see, of a strong median keel on the upper whorls, of a very weak 

 one at the upper suture and traces of a third one at the lower suture, which latter keel is 

 conspicuous on the last whorl, moreover very faint interstitial spiral striae, crossed by radiating, 

 threadlike striae. The nucleus and a great deal of the outer layer of the shell are wanting, its 

 beautiful nacreous inner layer being visible in many partS; in consequence the sculpture is only 

 visible on some small parts, as other parts have still suffered of corrosion; the columella and 

 umbilicus have the same character, as in the preceding species. The outer margin of the aperture 

 is quite defective, as well as the basal sculpture. In these circumstances I have not ventured 

 t.i name the species, nor have I accurately described it, though it will be probably new. 



uenzia monocingulata Seguenza. 



Seguenza. Buil. del Com. Geol. Vol. VII, 1870. p. 188. 



VERRILL. Trans. Connccticut Acad. Vol. VI, 1882 — 85, p. 186 (forwosa). 

 TRYON. Man. of Concli. Vol. IX, p. 46, PI. 8, lig. 71. 



Stat. 137. o°23'.8N., \2]' zij E. Between Makjan and Halmahera. 472 M. Fine, dark, muddy 



sand. 2 Spcc. 

 Stat. 241. 4°24'.3S., I2y°49'.3 E. Banda Sea. 1570 M. Dark sand with small stones. 1 Spcc. 



These specimens have much puzzled me, those from the two stations being considerably 

 different. That from Stat. 241 is more slender and lias a coarser sculpture, somewhat different 

 from the specimens collected at Stat. 137. The reasons that I have united them to the Atlantic 

 S. monocingulata are: the greal variability of that species, as already stateil by Dall in his 

 publication on the "Blake" Mollusca, quoted before in dealing with 5. Dautzenbergi\ the differences 



74 



