414 MESSRS. A, ADAMS AND G. FRENCH ANGAS [NoV. 10, 



75. Melania petenensis, nov. spec. 



T. elongato-pyramidalis, soJidiuscula, olivacea vel nigrescens, striis 

 brunneis ornata, plerumque apice eroso; anfract. 6-7, superst. 

 sulcis confertis longitudinalibus et continuis regulariter ornati, 

 planiusculi; sutura mediocris ; apertura elongato-ovata, albida; 

 columella paullulutn producta nee effusa ; peristomium tenue, 

 arcuatum ; operculum ovatum. 



Long. tot. 29, lat. 10 ; apert. long. 10, lat. 5 mill. 



Hab. Lake Peten, Vera Paz. 



76. PoMUS coltjmbiensis, Sow. 

 Hab. Lake Peten, Vera Paz. 



TT. PoMus giganteus, nov. spec. 



T.globosa, solida, profunde et anguste umbilicata, pallidissime 

 olivacea, sed apice viridi ; spira exserta ; anfract. 7, rapide ac- 

 crescentes, ad suturam acute angulati, ultimus turgide efflatus, 

 duo ultimi fortiter et irregulariter reticulati liris innumerabili- 

 bus longitudinalibus et latitutinalibus intersectantibus {super 

 ult. anfr. plus quam 40 sulcos enumeravimus) ; apertura semilu- 

 naris, nitida, splendide purpurea, lineis intensioribus ad partem 

 superiorem ornata ; labrum tenue, subreflexum, acutum, mar- 

 gine columellari luteo. 



Diam. maj. 90, min. 8.5, alt. 95 ; apert. alt. 66, lat. 39 mill. 



Hab. Lake Peten, Vera Paz. 



78. Ampullaria lattrei, Reeve. 

 Hab. Lake Peten, Vera Paz. 



79. Unio ver^ pacis, nov. spec. 



T. oblonga, temds, compressa, postice valde compressa et expansa, 

 antice obtuse rotundata ; umbones parvi, rotundatati, ligamento 

 exserto et conspicuo ; epidermis olivacea, radiis obscurioribus 

 ornata; margo ventralis extremitate jmsteriore compressa et 

 incisa ; denies cardinales tenues, compressi, crenati ; impres- 

 siones musculares fortissimce et scaberrimce, testa intus nacreo 

 purpurea micans. 



Long. 45, lat. 25, alt. 16 mill. 



10. Descriptions of New Species of Freshwater Shells 



COLLECTED BY Mr. F. G. WaTERHOUSE, DURING J. M'^Do- 



NALL Stuart's Overland Journey from Adelaide to 

 THE North-west Coast of Australia. By Arthur 

 Adams, F.L.S., and G. French Angas, Corr. Memb. Z. S. 



1 . ViviPARA waterhousii. Ad. & Ang. 



V. testa turbinata, globoso-conica, late umbilicata, spira elatius- 

 cula, epidermide tenui fusco-viridi obtecta ; anfractibus con- 

 veccis, adsuturas subplanatis, fasciis tribus vel quatuor angustis 



