REVISION OF RECENT BAIRDIIDAE 35 



Diagnosis. — Carapace strongly compressed, with distinctly punc- 

 tate exterior; posteroventral margin of left valve denticulate, others 

 apparently smooth; anterodorsal and posterodorsal margins very 

 slightly concave, posterior end slightly caudate. 



Material. — A single subfossil carapace (USNM 121280) in inter- 

 tidal sand at station LK-12, Galle, Ceylon. 



Distribution. — Described by Brady and A. Scott from Ceylon 

 and the Gulf of Manaar; probably not the same species reported by 

 Brady and Chapman from Samoa, Fiji, and Funafuti (= A^". pateri- 

 formis, new species) . 



Affinities. — Neonesidea pateriformis , new species, is similarly 

 compressed but without any angles or concave segments in lateral 

 outline, without any caudate termination. 



Neonesidea pateriformis, new species 



Figures 13-15 



Bairdia tenera Brady, Brady, 1890, p. 493, pi. 1: figs. 11-12. — Chapman, 1902, 



p. 422. 

 Species BC, Haddocks, 1966, p. 47, fig. 23. 



Etymology. — Latin patera, saucer -\- forma, shape. 



Type specimens. — Holotype adult male USNM 121281; allotype 

 female USNM 121282; paratypes USNM 121283-121284, 98553 

 (specimen 464), 98547 (specimen 463). 



Type locality. — Nosy Be, Madagascar, sample 523 (washings of a 

 green alga encrusting on rocks at low tide level at Navetsy). 



Diagnosis. — Carapace entirely smooth, lateral outline almost per- 

 fectly symmetrical without angles or posterior caudation, venter only 

 very slightly sinuate. Posteroventral margins of both valves with 

 numerous minute denticles. Color nearly uniformly dark brown 

 centrally, margins clear. 



Material. — Nosy B6; 14 living specimens, 24 subfossil specimens. 



Ifalik Atoll; 14 living specimens. 



Mombasa, Kenya; single living specimens in samples LK-28 and 

 LK-29. 



Habitat. — Nosy B6; on algae, dead coral fragments, and other 

 attached invertebrates and in associated sand in reef and platform 

 environments. 



Distribution. — Nosy B6, Ifalik Atoll, Mombasa. 



Reported (as B. tenera) by Brady at Somoa and Fiji, and by 

 Chapman near Funafuti. 



Dimensions.— Adult male USNM 121281 from Nosy Be, left 

 valve, length 0.79 mm, height 0.46 mm; right valve, length 0.80 mm, 

 height 0.42 mm. 



