Y L D I A 



Species 4. (Mus. ISrit.) 

 YoLDiA TENELLA. Yol. iestd parvtl, tenu'i, injlatil, 

 sv.hpeUucidd, ImvigatA, subtrapeziformi, minutis- 

 sime slriald ; latere postico siibaUenuato, subros- 

 trato, lunuhl valde depressd, complanatd, medio 

 contracto apice subcentrali ; lat -.re antico inflato, 

 lato, siibtus hiante, subrolundo. 

 The thin little Yoldia. Shell small, thin, inflated, 

 subpellucid, smooth, slightly trapeziform, very 

 minutely striated ; posterior side rather attenu- 

 ated, slightly rostrated, lunulo much depressed, 

 flattened, middle contracted, apex subcentral ; 

 anterior side inflated, wide, gaping beneath, rather 

 rounded. 

 Hinds. Proc. Zool. Soc., 1843, p. It'.). 

 Hah. Singapore. 



This is one of the four species enumerated by Mr. 

 Hanley as intermediate between Ijeda proper and 

 Yoktia. From its anterior ventral hiatus, and general 

 form, it appears most closely related to the latter, 

 although placed by the above-named author in the 

 fonner. 



Species 5. (Fig. a, b, Mus. Brit.) 

 Yoldia SEROxtNA. Yol testd ovato-mbrhomboided, 

 tenui, suhcompressd, lavigatd, alhidd ; latere 

 postico paulo loiujiore, subattemtato, compresso. 

 hand sulcata, superne cuneato, obscure unicostato, 

 lunuld elongatd, dktinctd, compressd ; mnlio sttb- 

 planulato, apice acuto, margine rentrali vix con- 

 tracto ; latere antico brevitlsculo, distanter et tenuiler 

 svhconcentrice sulcata, suprd medium ad terminum 

 rotunde subacuminato. 

 The evening Y'oldia. Shell ovate-subrhomboidal, thin, 

 subcompressed, smooth, whitish, posterior side a 

 little the longer, a little attenuated, compressed, 

 not sulcated, cuneate above with an obscure rib, 

 lunule elongated, distinct, compressed, a little 

 flattened in the middle, apex acute, ventral mar- 

 gin a very little contracted ; anterior side rather 

 short, distantly and finely concentrically sulcated ; 

 roundly acuminated at the end above the middle. 

 A. Adams. Proc. Zocl. Soc, 1856, p. CO. 



February 



Hab. Borneo. 



The posterior side forms an oblique triangle, wl 

 surface is free from the fine sulci which traverse 

 middle and anterior. 



Species 6. (Mus. Brit.) 



Yoldia Nicoharica. Yol. testd roseo-subaurantia, 

 ovatd, solidd, sidmquilaterali, latere postico sub- 

 altenuato, superne acuminalo, Icevigato, depresso, 

 lunuld disiincta, eariniformi ; latere antico sub- 

 injlato, paidb longiilsculo, lain, ad terminum ro- 

 lundo, striis minimis oblique concentricis scidplis. 

 The Nicobai! Yoldia. Shell rather orange-pink, 

 ovate solid, subffiquilateral ; posterior .side a little 

 attenuated, acuminated above, smooth, keel- 

 shaped ; anterior side rather inflated, a little 

 longer, wide, rounded at the end, sculptured with 

 very small obliquely concentric striae 

 Chemnitz. Conch., vii., PI. 194,/. .J41. "Area lajvigata 



pellucida Nicobariea." 

 Ilab. Nicobar Island. 



The anterior side is a very little longer than the 

 posterior, which latter is a little pointed, and is desti- 

 tute of the close stria; by which the anterior is 

 sculptured. 



Species 7. (Mus. Brit.) 



YciLDiA LEPiDULA. Yol. testd ovato-suhrhomhoided, 

 partim striata albo-lutescenti ; latere postico paulo 

 longiore, s^tpra subacuminato, infrh oblique sub- 

 truncato, Icevigato, lunuld compressd, distinctd, 

 elongold ; latere antico breviore, striato, ad termi- 

 num vix acuminato. 



The smart little Y'oldia. Shell ovate, subrhomboi- 

 dal, partly sti-iated, yellowish white ; posterior 

 side a little longer, slightly acuminated above, 

 obliquely subtruncated beneath, smooth, lunule 

 compressed, distinct, elongated ; anterior side 

 shorter, striated, very little acuminated at the end. 



A. Adams. {Yoldia.) Proc. Zool. Soc, 185G, p. 50. 



Hctb. Borneo. 



, 1871. 



