GLAUCONOME, 



Genus Glauconome, Gray. 



Testa oblongo-ocalis, tenuis, eequivalvis, subventricosa, 

 incsquilateralis, an/ice rotundato, postice plus minusve 

 attenuata, epidermide viridescente, tenui, corned in- 

 duta. Cardo dentibus in utrdque valvd tribus, posti- 

 cis majoribus, valve dextralis medio, sinistralis pos- 

 tico, bifidis. Impressiones musculares in utrdque 

 valvd dine, antica marginalis, oblonga, postica sub- 

 quadrata. Pallii impressio muscularis sinu magno, 

 antice obtuso. Ligamentum externum, oblongum. 



Shell oblong-oval, thin, equivalve, slightly ventricose, 

 inequilateral, rounded anteriorly, more or less at- 

 tenuated posteriorly, covered with a thin epidermis, 

 which is sometimes inflected over the margin. 

 Hinge ; three teeth in each valve, the posterior of I 

 which are the larger, middle tooth of the right 

 valve and posterior of the left valve bifid ; no lateral 

 teeth. Muscular impressions, two in each valve, 

 the anterior marginal, oblong, the posterior some- 

 what square. Muscular impression of the mantle 

 with a large sinus, obtuse anteriorly. Ligament 

 external, oblong. 



The genus Glauconome was introduced some years 

 since by Mr. Gray in his ' Spicilegia Zoologica,' with 

 the description of a single species collected by John 

 Reeves, Esq., in China; another species appears to have 

 been described by the great author of the ' Systema 

 Natura,' under the title of Solen virens (the original 

 examples of which are still preserved in the Museum of 

 the Linnean Society), and I have now the pleasure of 

 adding seven new species, which materially increase the 

 generic importance of the group. 



The Glaucoiwmes are of a light semiperlaceous struc- 

 ture, covered with a thin light-green horny epidermis, 

 which in some species is very peculiarly wrinkled or 

 shrivelled and inflected over the margin ; and their 

 hinge is composed of three irregularly forked teeth in 

 each valve, some of which are bifid, the valves being 

 united by an oblong external ligament. They live in 

 brackish water (partially imbedded in the mud), in the 

 mouths of rivers at their confluence with the sea, and 

 have only been found as yet in the eastern hemisphere. 

 Of the nine species above alluded to, the localities of eight 

 are known to be as follows : — one inhabits the rivers of 

 China, one the Ganges, three inhabit rivers running i 

 into the Bay of Manila, and three inhabit rivers in the , 

 islands of Zebu, Negros and Luzon of the Philippines. J 



The place selected by Mr. Gray for the genus Glau- 

 conome in the natural system was in his family of Vene- 

 rida : it appears to me, however, to exhibit a much 

 stronger affinity with the Solenacea ; in my ' Conchologia 



Systematica ' I referred it to that family, and the pro- 

 priety of this removal has been subsequently confirmed. 



Species 1. (Mus. Cuming.) 



Glauconome Chixensis. G/auc. testa elongato-oblongd, 

 striatd, circiter umbones erosd, lateribus rotundatis, 

 postico subangulato-attenuato. 



The Chinese Glauconome. Shell elongately oblong, 

 striated, eroded about the umbones, sides round, 

 posterior rather angularly attenuated. 



Gray, Spicilegia Zoologica, p. 6. pi. 3. f. 13 and 13 «. 

 Sowerby, Genera of Shells, No. 4:2. 



Ilab. Rivers of China. 



This species is generally much eroded. 



Species 2. (Mus. Cuming.) 



Glauconome straminea. Glauc. testd subelongato- 

 ovatd, circiter umbones erosd, latere antico rotundato, 

 postico subattemiato, leviter angulato, rotundato ; 

 epidermide nitidd, viridescente -sir amined, unguium 

 super corrugatd. 



The straw-coloured Glauconome. Shell rather elon- 

 gately ovate, eroded about the umbones, anterior 

 side rounded, posterior somewhat attenuated, an- 

 gularly rounded ; epidermis thin, light greenish 

 straw-colour ; wrinkled on the angle. 



Reeve, Pro. Zool. Soc, 1844. 



Hab. Mouths of rivers running into the Bay of Manila. 



A light delicate shell slightly angulated on the ante- 

 rior side, with the epidermis lying on the angle in 

 wrinkles. 



Species 3. (Mus. Cuming.) 



Glauconome radiata. Glauc. testd oblongo-ovatd, 

 compressiusculd, earned, purpureo-radiatd, epider- 

 mide viridescente prope marginem indutd, lateribus 

 rotundatis, postico subacuminato. 



The rayed Glauconome. Shell oblong-ovate, lather 

 compressed, flesh-colour, rayed with purple, co- 

 vered near the margin with a light greenish epi- 

 dermis, sides rounded, posterior a little acuminated. 



Reeve, Pro. Zool. Soc, 1844. 



Hab. Mouth of a small river at San Nicolas, island oi 

 Zebu, Philippines (found in sandy mud at low 

 water) ; Cuming. 

 The only species rayed externally with purple. 



Species 4. (Mus. Cuming.) 

 Glauconome rugosa. Glauc. testa e/ongato-oblonyti 



April 1S44. 



