GEOLOGY. 



65 



sented in this Museum, but it has lately received two splendid 

 additions by the acquisition of the famous collection of the Earl of 

 Enniskillen, from Florence Court, Ireland ; and that of the late Sir 

 Philip de Malpas Grey-Egerton, Bart., M.P. (Trustee of the British 

 Museum), of Oulton Park, Tarporley, Cheshire ; both obtained within 

 the present year (1882). 



The incorporation of these large collections, and the introduction 

 of twelve additional Table-cases into this Gallery, prevents a detailed 

 account of its contents being given at present. A full description 

 will shortly be issued in a subsequent Edition of the Guide. 



This terminates the series of Vertebrate fossils, and in the next 

 Gallery we commence with the Invertebrata (animals without a 

 backbone)— such as Cuttlefishes, Snails, Oysters, Insects, Crabs and 

 Lobsters, Worms, Sea-urchins, Corals, -&c. 



INVERTEBRATE ANIMALS. 

 Division A. Mollusca (soft-bodied animals). 

 Class 1. — Cephalopoda. 



Narrow Gallery No. 2 has just been fitted up with Wall-cases, and 

 sixteen Table-cases for the display of the fossil Cephalopoda,* being 

 the first section of the Invertebrate animals and the highest division 

 of the Molluscan Class. 



The animals of this class are all marine, and are provided with 

 long feelers or tentacles (sometimes called feet) attached to the head 

 around the mouth, whence the name Cephalopoda, or " head-footed," 

 is derived. Here are placed the fossil representatives of the 

 existing Octopus, and the Squids and Cuttlefishes, the delicate Paper 

 Nautilus and Spirula, also the Pearly Nautilus. These are divided 

 into two great groups, the Dibranchiata, or two-gilled, and the 

 Tetrahranchiata, or four-gilled Cephalopods. 



The first of these includes the most active free-swimming forms to 

 which all the living genera belong, save one solitary survivor, " the 

 Pearly Nautilus." 



Most of them have a delicate internal shell, often quite minute or 

 rudimentary, as in Octopus, or divided into chambers by septa or 

 partitions, as in Spirilla. 



The delicate shells of Spirulirostra, Beloptera, &c, occur in the 

 Miocene and Eocene Strata. Impressions of " Squids " showing the 

 soft parts of the body, the arms, and the " ink-bag" are found in the 

 Chalk of the Lebanon, Syria; the Oxford Clay of Wiltshire; the 

 Solenhofen Limestone of Bavaria ; and the Lias of Lyme Regis, &c. 



The " Belemnite,'' so common a fossil in the Cretaceous and Oolitic 

 rocks, is only the shelly extremity or " guard" (like the tip of a spear, 

 or dart, without barbs), forming part of the internal shell of an extinct 



* From Ke<pa\f], head, and irovs, 7robos, a foot ; hence "head-footed." 



