28 



HA.P.DW1CKE'S SCIENCE-GOSSIP. 



uer similar to that by which iron is strengthened 

 by being corrugated. And, last of all, the divisions 

 between the chambers serve as supports, acting as 

 cross-beams, and enabling the shell to resist all 

 lateral and inward pressure. Probably more of the 

 living animals have been lately observed, as they 

 are by no means rare in the Indian seas, their 

 favourite haunts being along the coral reefs. The 

 Eiji Islanders are said to catch them by letting down 

 large wicker baskets of the same construction as 

 ordinary crab-pots, baited with crayfish, and loaded 

 with stones to make them sink. After catching the 

 Nautili they broil them, when they are reputed to 

 be very good eating. 



Fig. 2-1. ConiatH's spftirru-tts. from Carboniferous formation, 

 showing angulated chambers. 



Of the second family, the Orthoceratidci', we have 

 no examples, save in the fossil state. In the typical 

 genus, Orthoceras (opQoQ,orthos, straight, and Kipaq, 

 keras, a horn), the shells are straight, and, as their 

 name implies, very like a straight horn. Like the 

 Nautilus, these shells are multilocular, and have 

 their chambers separated by transverse plates, con- 

 cave externally, convex internal])', and connected 

 by a siphunele. Some species of this genus attain 

 to a length of nearly six feet ; their shells are 

 found in great numbers in blocks of marble of a 

 dark-red colour, from the limestone of Oeland. Of 

 this marble many pavements of our public buildings 

 have been constructed; amongst them part of that 

 in Hampton Court Palace, and that in the Hall of 

 University College, Oxford. Several other genera 

 belonging to this family possess shells of very 

 pretty and varied forms ; of these, the genera 

 Cyrtoeeras and Gyroceras, are good examples. We 

 now reach the last family, the Ammonitido', contain- 

 ing the well-known Ammonites and other kindred 

 forms, which must have existed in great numbers 

 during the Secondary epoch, as testified by the 

 number of their shells which have been found. They 

 are very similar to the Nautilus in most respects, and 

 .are far too well known to require description. The 

 name of Ammonite is said to be derived from the 

 Romans, who called it the "cornu xVmmonis," or 

 Amnion's horn. Another name is that of St. Hilda's 

 beads, so called from a supposition that they were 

 •3nakes turned into stone at that saint's prayer. 



The good people of Whitby went farther than this, 

 for they made plaster heads of snakes and fixed 

 them on to the Ammonites ; alleging that they were 

 found in that condition. Ammonites are occasion, 

 ally found of a great size, almost as large as a cart- 

 wheel, and in some parts are so plentiful as to be 

 used for mending the roads. They are very gene- 

 rally distributed, most numerous in portions of the 

 Oolitic system ; two species found in England, at 

 Whitby, have also been discovered at an elevation 

 of sixteen thousand feet on the Himalavas. 



m 



IS* 



ll i 



Fig. 25. Ortltocerns ; the upper 

 part is one of the perforated 

 chambers. 



Fiff. 26. Curved 

 Orthocerus {Cyrtoeeras). 



It nov.' only remains for me to notice a class Oi 

 shells which, from their structure, might be sup- 

 posed to be closely connected with the Ammonites 

 and other chambered shells ; I allude to the Eorami- 

 nifcra, and more especially the Nummulites. These 

 beautifully sculptured little shells, existing as they 

 do in countless myriads on our coasts, the delight 

 and great pleasure of the microscopist, are of much 

 lowlier rank. They appear to be more closely allied 

 to the Amceba, animals (very nearly vegetables), 

 notliing more than a piece of mucus, colourless, 

 plastic, and just retaining voluntary motion. When 

 one of tliese creatures approaches any minute plant 

 or animal that cannot get out of its way, it so con- 

 torts itself as to send out brauolies or arms of its 

 body, which clasp the prey all round, and make it 

 embedded in the living mucus until quite absorbed. 

 Thus, of very much lower organization than the 

 Cuttles are the Foraminifera. 



