1NVERTEBRA TBS. MOSQl 1T0 A 1 



Arthropods include the familiar crabs, lobsters, insects and their rela- 

 tives. The Dumber <>f existing speciea in this group is 



. . greater than that, of all the rest of the animal and vegetable 



Arthropods ^ 



kingdoms together. No other group comprises so many 



species useful or harmful to man. In the case in the center of the alcove 



is a model showing the anatomy of the common lobster, 



Crustaceans , , , r , , . , , - . .. 



also enlarged models snowing heads ot various species <>t 



insects. On the wall are two of the largest specimens of 



lobsters that have ever been taken. They weighed when alive thirty-one 



and thirty-four pounds respectively. The largest of the arthropods is the 



giant crab of Japan, some of which, like that placed on the wall, have a 



spread of about ten feet. 



The mollusks form a group second only to the arthropods in the vast 



number and diversity of forms which it embraces, including marine, fresh 



water and land animals. All mollusks have soft bodies but nearly all of 



them secrete a shell which in manv species is of pearly mate- 

 Alcove ii 

 Mollusks r * a ^ ( mot h er -°f-P ear l) • Well-known examples of this group 



are the common clam and oyster and enlarged models in the 

 Model of center ease show the anatomy of these species. The largest 



species is the huge ' bear's paw" or furbelowed clam of the 



eastern seas. 



Vertebrates include the largest, most powerful and most intelligent of 



animals. This group culminates in man who still bears 

 Alcove 12 

 V * b t witness to his chordate ancestry in the retention of a chorda 



(cartilaginous spine), and gill clefts during embryonic life. 

 Among these ancestral forms are the Ascidians, or Sea-squirts, an enlarged 

 model of which is shown in the central case, while others are shown among 

 the animals on the wharf-piles in the window T group. The models in the 

 central case show the development of the egg of typical vertebrates. 



An exceptionally large specimen of beautiful madrepore coral is in the 

 case near the entrance, and the associations of marine life that may be 



found among the coral reefs of the Bahamas are represented 



by several small groups in the center of the hall. Certain 

 of the groups in this section of the hall illustrate various biological principles 

 associated with the name of Darwin. The variation in form, size and 

 color of the snail and the variation of the shell of the common scallop are 

 graphically shown. 



Four large models in the center of the hall show the mosquito which is 



the agent in the spread of malaria. These models represent 



, ■»» , . , the insect enlarged seventy-five diameters or in volume 

 the Malarial ° , . , , . ™ 



Mosquito * our hundred thousand times the natural size, ine mos- 



quito in its development undergoes a metamorphosis. The 

 model at the left shows the aquatic larval stage; the larva 3 are the "wrig- 

 glers" of our rain water barrels. The next model is the pupal stage, also 



