14 SYRIAN MOLLUSCAN FOSSILS. 



The Gasteropods of the Thomson and Congregational House collections 

 agree in rock material with those of the Bird collection, and were sent home 

 from Beirut by American missionaries, one of whose principal stations is 

 Abeih. It is therefore altogether probable that they were procured from 

 that locality, since it yields the most abundant and attainable supply. But 

 to guard against possible error, we will, in our discussion of the several 

 species, speak of them as probably from the Beirut district, — already 

 defined. The specimens of the Merrill collections, with a few exceptions, 

 we know to be from that district. 



Lunatia Gileadensis. sp. nov. 



Plate l, Us. l. 



Testa ponderosa, ghboso-turbhuda : spira elaia, aculiuscula : anfracius circUer 

 quingue rotundati, subito crescentes, prope marginem posteriorem subdepressi; swbura 

 perspicua: apertura lunata; labium postice calloso-reflezum ; umbilicus apertus an- 

 gustior, pervius, sine funiculo. 



Shell thick and heavy, globosely turbinated: spire elevated, rather sharp: 

 whorls about five, rounded, slightly depressed al the posterior margin ; 

 suture well marked; aperture semilunar; columellar lip callously reflexed 

 behind ; umbilicus open, rather narrow, pervious, not funiculate. 



Single specimen, with portions of the body-whorl broken away. Length. 

 87 mm., original length about 95 mm. ; width, 7G mm., originally about 

 85 mm. 



This species most resembles the recent Imncdia heros Say. differing from 

 it chiefly in having a more elevated spire, and the body-whorl rather more 

 produced anteriorly. The umbilicus is not narrower than is seen in many 

 specimens of heros. 



The specimen is completely silicified, and is incrusted without and within 

 by a layer of siliceous concretions. The concretionary layer (perhaps de- 

 posited while the fossil lay in a cavity) is of moderate and uniform thickness, 

 as is evident from the fact that the shell retains the just proportions of all 

 its parts. The thickness of the outer lip and parts adjacent ranges from 

 7 mm. to 9 mm., as measured upon the fractured edge and along a section 

 exposed by the removal of a triangular portion broken out in procuring 

 the specimen, but cemented back in place before the figure was drawn. The 

 shell must therefore have been originally of unusual thickness, far ex- 

 ceeding in this respect the most ponderous species of recent Nevetitce, 



