November 



c8 9 i] 



THE HUMMING BIRD. 



85 



tropical and temperate regions, and occasionally on 

 the British coasts. It is the largest living Chelonian 

 known, exceeding a length of six feet. The 

 Cheloniidae, or Marine Turtles. These turtles are 

 thoroughly marine animals, their fin-like feet and their 

 light shell rendering them the best swimmers in the 

 class of reptiles. They are found sometimes several 

 hundred miles distant from the shore, where they 

 return periodically to lay from 100 to 200 soft-shelled 

 eggs, which they bury in the sand. The American 

 Indians, who know exactly the time when they lay 

 their eggs, come in numbers, with their wives and 

 children, to gather them. Armed with a pointed stick, 

 they feel the spots where the eggs are supposed to be, 

 and soon discover them. They also secure a 

 large number of turtles and feast on them during 

 tnany days. Caretta imbricata, or Hawk's-bill 

 Turtle, is the species which furnishes the com- 

 mercial tortoise shell. The finest sort comes from 

 Celebes. Some fine shells are also found in the Gulf 

 of Mexico ; the Trionychidae, or Fresh-water Turtles ; 

 iheEmydidae, or Fresh-water Tortoises. Macrodemmys 

 temminchii is the largest species. Its tail attains a 

 great length, and it is furnished with a crest resembling 

 that of a Crocodile. The Mata-mata, Chelys fi,7nbriata 

 of Guiana, also a fresh-water Tortoise, is very remark- 

 able. Its head and neck are fringed with warty 

 appendages, floating in the water like some vegetable 

 growth, whilst the rough boned carapece resembles a 

 stone, an appearance which is of great use to this 

 creature in escaping the observation of its enemies as 

 in alluring to it unsuspicious animals, on which it 

 feeds. Lastly comes the Testudinidae, or Land 

 Tortoises, amongst which are included the gigantic 

 Tortoises which were formerly very common in the 

 Mascarene and Galapagos Islands, where they could 

 be captured in any 'number with the greatest facility. 

 They weigh from 100 to 300 pounds. The large male 

 specimen of Tertudo elephantina exhibited weighed 

 870 pounds. The gigantic Land Tortoise of Abingdon 

 Island, Testudo abingdoni, is remarkable for its long 

 neck and its thin shell. That species is supposed to 

 be extinct now. 



STAR FISH GALLERY. 



The Star Fish Gallery contains a selected series of 

 the animals belonging to the class Echinodermata, of 

 which the Star Fishes are one of the best-known 

 types, but which besides includes also the Crinoids, 

 Sea-Urchins and Sea-Cucumbers, or Sea-Slugs. 



A small collection of Vermes^ or Worms, is also 

 exhibited in this Gallery. 



Echinoids live on seaweeds and the animals that 

 are found on them. Such as have no teeth, like 

 Spatangus (Case 6), use their spout-like mouth to 

 take up the sand and débris on which they move, and 

 from which they extract some nourishment. Ophiu- 

 roids live on the smaller Foraminifera ; Asteroids on 

 dead fishes, Oysters and Mollusks ; Holothurians on 

 shell or coral débris, and the minute organism it con- 

 tains ; and Crinoids on small tests of Foraminifera, 

 on Larvse and on small Crustacea. 



Echinoderms move but little ; the unstalked 

 Crinoids, if they cannot find stones around which to 



attach themselves, swim by beating the water with 

 their delicate arms, five being raised and five depressed 

 alternately. They are often of exceedingly bright 

 colours, and are very conspicuous objects. Some- 

 times they cover themselves over with seaweed, and so 

 hide their brilliancy. The spines of some forms are 

 exceedingly painful to the touch, and the stout plates 

 of some of the Goniasters must form admirable 

 organs of protection. 



The power of restoring lost or injured parts is one 

 of the most remarkable points in their organisation. 



Echinoderms are of great geological age, and were 

 very abundant in earlier periods. Two groups 

 (the Blastoids and Cystids) have completely dis- 

 appeared, and the Stalked Crinoids are far less 

 common than they used to be. They are found in 

 all seas, and extend to a great depth of the ocean. 

 They are most abundant in tropical seas. 



Most Echinoderms lay their eggs in the water 

 where the larvae are developed and swim about 

 freely ; but in a few, the young do not pass through 

 any metamorphosis, the eggs being received in special 

 pouches of the body of the parent, in which they are 

 hatched. 



The Echinoidea, or Sea-Urchins, are used as food in 

 Italy and other countries. They are eaten raw or 

 cooked. 



Echinodermata are classified as follows : — 

 Crinoidea, or cup-shaped Echinoderms, of which a 

 fine specimen, Pentacrinus decorus, can be seen in 

 Case 7. Asteroidea, or Star Fishes. Of this order, 

 a fine series of Asterias, Acanthasier, and Oreaster, 

 are exhibited. 



Op/tiuroidea, or Brittle Stars ; Echinoidea, 01 Sea- 

 Urchins, in which the rays are not free, as in the Star 

 Fishes, or Brittle Stars, but unite to form a compact 

 spherical heart, or dish-shaped test, covered with 

 spines, which sometimes attain a great length, as 

 shown in the fine example of Diadema setosa, from 

 Andamans ; and the Holothurioidea, or Sea Cucumbers, 

 in which order are exhibited various specimens of the 

 edible Holothurians, trepang, or bêche de mer, so 

 highly prized by Chinese. 



SHELL GALLERY. 



A large gallery has been devoted to the exhibition 

 of Shells, or Mollusca. It constitutes one of the prin- 

 cipal divisions of the animal kingdom, and includes 

 such animals as the Octopus, Cuttlefish, Snail, Slug 

 Whelk, Cockle and Oyster. 



They may be characterised as soft, cold-blooded 

 animals. Their heart consists of two or more 

 chambers, and is situated on the dorsal side of the 

 animal. It drives the blood into spaces between the 

 various organs of the body. Only the Cephalopods 

 possess internal cartilages, but without osseus 

 end skeleton. In the majority this is compen- 

 sated by an external hardened shell. This 

 shell may consist of two parts (valves), as in the 

 Oyster, or may be single, as in the Snail. Upon the 

 upper surface of the foot, in many Gastropods, a 

 flat, hard structure, termed the operculum, is situated, 

 which, when the animal is retracted, partly or entirely 

 I closes the aperture of the shell. 



