602 THE VOYAGE OF H.M.S. CHALLENGER. 



sharp barely prominent edge, behind which is an extremely obsolete furrow. H. 0"06 in. 

 B. 0-037. Mouth, height 0-027, breadth 0'022. 



This species somewhat resembles Eissoa quisquiliarum, Wats., but the shape of the whorls, and 

 the form of the apex and mouth are different, as well as the sculpture. 



28. Eissoa (Ceratia) pachia, 1 n. sp. (PL XLV. fig. 7). 



Station 122. September 10, 1873. Lat. 9° 5' S., long. 34° 50' W. Off Pernambuco. 

 350 fathoms. Eed mud. 



Shell. — Strongish, ovate, conical, subtransparent, with a smallish rounded tip, convexly 

 conical whorls, a scarcely impressed suture, a produced base, a varixed lip, and a roundly 

 ovate mouth. Sculpture : Longitudinals — besides lines of growth, there are feeble, narrow, 

 rounded riblets, which die out on the base. Spirals — the whole surface is scored with 

 feeble rounded threads, parted by faint flat furrows about twice their breadth ; the suture 

 is marginated below by a strong rounded thread, defined by a small but distinct furrow ; 

 the first 2^ whorls are smooth. Colour translucent. Spire short, broad, and conical. 

 Apex small relatively to the shell, rounded. Whorls 5, conically convex on the side ; of 

 rapid increase, the last in particular being large and tumid. Suture scarcely oblique, 

 very slightly impressed. Mouth roundly ovate, narrowed, and bluntly pointed above. 

 Outer lip sharp, patulous, with a slight and rather remote varix externally. Inner lip 

 thin, defined, straight on the body, sharp-edged, straight and patulous on the pillar, where 

 there is behind it a very small furrow and umbilical chink. H. 0'093 in. B. 0'062. 

 Mouth, height 0*044, breadth 0-039. 



This species is not unlike Eissoa euchila, Wats. ( = Eissoa novarensis, Wats., nee v. Frauenfe ldt *) 

 but is somewhat broader in proportion to length, with a shorter spire, a flatter and less pointed 

 base; the apes is blunter, the whorls more depressed; the outer lip, near its junction to the body, 

 is less roundly arched, being here a little compressed. The sculpture is markedly different, and that 

 on the apex of Eissoa euchila is wanting here, where the apex is quite smooth. Eissoa turgida, 

 Jeffr., has a still blunter and more depressed apex, the whorls of the spire are slightly broader, and 

 the last two whorls are smaller; thus the whole shape is different, and in his species the sculpture is 

 more obsolete. 



1 iraj^v;, xa^iiix, stout. 



2 The identification of my Madeiran species '(see Proc. Zool. Soc. Lond., 1873, p. 377, pi. xxxv. fig. 13) 

 with that of v. Frauenfeldt was made on the authority of Baron Schwartz von Mohrenstern, that species being 

 unknown to me ; nor was I aware it had been published six years earlier (in the Moll of the " Novara " Exped., 

 1867, p. 11). A comparison of his figure (pi. ii. fig. 16) makes it impossible to believe that the two shells can 

 belong to one species. I have accordingly changed the name of the Madeiran shell as above. 



