126 



posterior margin is distinctly arched about the middle, but not so angulated as in L. anguîatn ; 

 the sculpture consists of moderately raised, inequidistant, radiate, thread-like ribs ; the ribs are 

 much more prominent and distinct but less numerous than on the shells of L. angulata ^). The 

 hinge-line is comparatively broader than that of L. angulata, but has a shorter though deeper 

 cartilagenous pit. I give below the comparative measurements (in millimètres) and figure shells 

 of the two species on pi. III. 



L. orientalis L. angulata 



Length 22.8 32.2 



Height 34 30 



Diameter 16 16.2 



Probably most of the records of L. angulata by différent authors from round Australia 

 are to be referred to this species. In the absence of the spécimens I am unable to décide which 

 species from Madras was recorded by Melvill & Standen ■) under the name L. angjtlata. 



Distribution : — L. {L.) orientalis appears to be confined to the Southern Pacific area, 

 round the Philippines, Australia, New Zealand, and its range probably extends through the 

 South China Sea into the Gulf of Siam. 



The "Siboga" Expédition obtained a single shell at Elat, West coast of Great Kei Island 

 in the Banda Sea (St. 261). 



7. Lima [Limaria^ fenestrata sp. nov. (Plate III, fig. 36). 



191 1. Lima fenestrata Pelseneer, "Siboga" Lamellibranches (Anat.), p. 34, pi. X, fig. 10 (without 

 description). 



The available material of this new and interesting species is unfortunately limited to a 

 single shell of which the right valve is badly broken. As the species is, however, so distinct 

 from any previously described form and has been referred under the name Lima fenestrata in 

 the Anatomical part of the Report on the "Siboga" Lameliibranchia, I hâve thought it best to 

 describe the species. 



The following is a description of this new species : — Shell small, very thin, translucent, 

 subovoidal, moderately inflated, very inequilateral and oblique; anterior slope rather short, sub- 

 truncate, running gradually into the somewhat curved ventral margin ; posterior slope nearly 

 straight, much longer than the anterior slope; auricles narrow, subequal; hinge-area very narrow 

 with a shallow, subcentral ligamental pit; sculpture consisting of 14 low but distinctly raised, 

 thread-like, hollow, radial ridges separated by very broad interspaces; with a lens it is also 

 possible to distinguish fine, wavy, concentric threads; thèse are more prominent in the régions 

 marking off the growth rings; shell margin subdentate, colour pale white; inner surface dull 

 yellowish white. Length of single valve 13.6 mm., height 19.9 mm.; diameter 3 mm. 



Habitat: — The unique Holotype was dredged from a depth of 538 mètres at St. 316 

 (7°i9'.4S., ii6°49'.5E.) in Bali Sea. 



Remarks; — L. {^L^ fenestrata appears to be allied to Z. {L.) fragilis, but the shell ofthis 

 new species is much thinner, and more fragile; the sculpture and form also are very characteristic. 



1) I figure a shell (Plate III, figs. 34, 35) of Lima angulata Sowerby from Panama, for comparison. 



2) Melvii.l, J. C. & Standen, R. — Journ. Conch., IX, p. 80 (1898). 



