114 



Distribution : — S. inicrolcpos is confined to the Pacific Océan. 



The "Siboga" Expédition obtained a few shells from Sapeh Strait (St. 49 a), Bay of Badjo, 

 West coast of Flores (St. 50), Bay of Nangamessi, Sumba (St. 53), St. 98 (6°9'N., i20°2i'E., 

 350 mètres), Saleyer (St. 213) and at Sulu. 



8. Spondyhis tvrightiamis Crosse. 



1848. Spondyhis arniatus Sowerby, (nec Goldfuss), Thés. Conch., I, p. 424, pi. LXXXIX, fig. 53, 



1872. Spondylus Wriglitianus Crosse, Journ. Conchyliol., XX, p. 360. 



1873. Spondylus WrigJitianiis Crosse, Journ. Conchyliol., XXI, p. 253, pi. IX, fig. i, \a. 

 1884. Spondylus Wriglitianus Brazier, Proc. Linn. Soc. N. S. Wales, IX, p. 803. 



1884. Spondyhis victoriae var. zvrightianus Smith, Rept. Voy. "Alert", p. 114. 



1885. Spondylus victoriae var. wriglitianus Smith, "Challenger" Lamellibranchia, p. 286. 

 1890. Spondylus Wriglitianus Paetel, Cat. Conch. Samm., III, p. 240. 



191 5. Spondylus wriglitianus Fulton, Journ. Conch., XIV, p. 336. 



1916. Spondylus wriglitianus Hedley, Journ. Proc. Roy. Soc. West Australia, I, p. 158. 



19 17. Spondylus victoriae var. wriglitianus Odhner, Kungl. Sv. Akad. Handl., LU, n" 16, p. 8. 



Smith regarded Spondylus wrightiantis Crosse as a variety of 5". victoriae Sowerby, 

 but I agrée with Hedlf.y and Fulton that it is a distinct species. The shell of 5". ivrightiamis 

 is more ovoidal, its hinge-line much narrower, the spine rows more numerous (6 — 8), and the 

 spines on the upper valve straighter and not spreading outwards as in 5. victoriae. 



Distribution : — 5". ivrightiamis appears to be a fairly common species round the 

 Australian coasts. 



The "Siboga" Expédition dredged a single upper valve at vSt. 164 (i°42^5 S., i30°47'.5E., 

 32 mètres). 



9. Spondyhis serraticosta sp. nov. (Plate III, figs. 19, 20). 



The following is a description of this new species : — Shell medium-sized, suborbicular, 

 moderately solid ; upper left valve only slightly convex, lower right valve more inflated ; auricles 

 small ; sculpture of right valve consisting of 7 to 10 very low radial ribs, bearing thin, strong, 

 long, pointed spines much larger nearer the periphery, interspaces densely covered with small 

 hairy spines ; sculpture of left valve similar, but spines fewer and less strongly developed ; 

 cardinal area narrower in right than in left valve ; shell colour bright orange ; interior of shell 

 white to pinkish with a narrow band of orange along the margin of the valves. 



Length : 24.3 mm.; height 26.8 mm.; maximum diameter 14 mm. 



Habitat : — A single shell of this interesting species was brought up in a Blake Dredge 

 at St. 260 (5°36'.5S., i32°55'.2E., 90 mètres). 



Remarks : — 6*. serraticosta resembles 5". innltisetosns Reeve ^), but the radial ribs and 

 spines of the shells of this new species are less evenly developed and much less foliaceus than 

 in Reeve's species ; the colour and form of the shell of the two species are also différent. 



i) Reeve, L. — Conch. Icon., IX, Sforidyliis.^ pi. III, fig. ii (1856). 



