2 INTllODUCTIOX. 



specimens came from the vicinity of Beirut, Abeih, Dog River (Nahr el Kelb) a few miles 

 north of Beu-ut, and the mountains between this river and the Cedars, a mountainous 

 district which extends more tlian twenty and not over thirty miles north and south, with 

 Beirut and Dog Eiver as a centre." To this portion of country I shall refer for conven- 

 ience, in the following pages, as the Beirut district. 



The Bird collection was received also from Dr. Merrill in person, with the oral state- 

 ment that, as he understood, it was gathered at Abeih and in its vicmity. The fact that 

 some of the shells are of species already recorded as from that locality, and that the rock 

 material which makes up the fossils, adheres to them, or fills their interiors, is such as is 

 known to characterize the richly fossiliferous strata of Alxnh, constitutes strong internal 

 evidence that most of the specimens are actually from the place from which they are 

 said to come. Yet under the title Jurassic Ammonites (pages 9, 10) reasons are given 

 for the conclusion that the three species from the Bird collection there named could not 

 have come from Abeih, where only Cretaceous strata are known to occur, but must have 

 been taken from beds older than the Cretaceous, such as in all Syria, so far as at present 

 traced, are restricted to one narrow area, lying entirely without the circle of Beirut, and 

 upon the slope of Mount Hermon. 



Of the Thomson and Congregational House collections it can only be affirmed that 

 they are from "Lebanon," but the testimony of the specimens themselves goes to make it 

 very highly probable that all of them had their origin within what we have termed the 

 Beirut district. 



Of the fossils brought together from these different sources, as in the case of all other 

 collections from the same region of which any accounts have been published, it is mainly 

 tlie Gasteropods that have been preserved in any considerable degree of completeness. 

 Such specimens characterize the Bird collection, made up principally of choice tilings 

 selected apparently under the guidance of a taste which rejected whatever was displeasmg 

 to the eye. But of the greater number of Lamellibranchs, interior casts alone occur ; and 

 taking into account the like condition of things in other collections from the same strata, 

 and the nature of the beds in which they are enclosed, the probability seems very small 

 that of certain genera better representatives wUl ever be discovered. 



In dealing with such specunens, one is at once confronted with the question how far 

 it is useful— not to say alloivabk — to attempt the description of species from well- 

 preserved casts which bear positive generic characters, but exhibit few of the superficial 

 markings upon which the distinctions of species largely depend. While settling for liim- 

 self this question, the student is likely to remember the censure which has been unspar- 

 ingly visited upon several eminent palaeontologists for presuming to confer specific names 

 upon casts denuded of then- tests, nor will he forget that later investigation has in signal 

 instances justified their action. 



The question is, perliaps, one of more interest in the study of molluscan fossils of the 

 Cretaceous period, than with reference to those of any other. For while, for example, m 

 determining the Cretaceous shells of Southern India and those of California and the Upper 



