64 , Guide to the Invertehrata. 



Bryozoa. America ; its importance to English students is largely due to the 

 GALLEKY fact that it includes specimens belonging to genera found also in 



England, but which are here in such unsatisfactory preservation 

 cases that their structure cannot be adequately determined. 



sea & 86b, The Carboniferous fauna of ]!^orth America contains some 

 12a. remarkable forms, notably the screw-like Archimedes Wortheni, 



from Warsaw, Illinois, and Evactinopora quinqueradiata, from 



Burlington, Illinois. 



A collection from the Bathonian deposits of Northern France 



on the middle slope contains several interesting forms, notably 



two species, Memlranipora jurassica and Onychocella JlabelU- 



formis, which are the first known representatives of the true 



Cheilostomata. 



Among the Tertiary Bryozoa, the large specimens from the 



Miocene deposits of the Mediterranean are most worthy of notice. 



(Division A.— ARTHEOPODA.) 



GALLERY This division comprises the Insecta, the Myriopoda, the 

 Arachnida, and the Crustacea. In these animals the body is 

 12 Table- composed of a series of segments united together in a linear order 

 case 85. and the number of which is usually definite. Each segment may 

 have a single pair of jointed appendages articulated to it, and 

 both are encased in a chitinous or calcareous covering more or less 

 thick. The muscles, nerves, and internal organs are all enclosed 

 within the hard external covering, which thus protects them from 

 injury. The breathing organs, when present, may be in the form 

 of gills or branchiae, or pulmonary sacs or tracheee. 



III.— TRACHEATA. 

 Fossil I — Insecta (or Hexapoda). The Insects form the most specialized 



_ , ' group of the Arthropoda. The head, thorax, and abdomen are 



Wail -Case 



12, Table- distinct ; there are three pairs of legs borne on the thorax ; the 



case 86. abdomen has no limbs; the head bears a single pair of antennae; 



most insects have two pairs of wings on the thorax, and they 



breathe by means of trachese. 



The earliest known evidence of insect-life is the wing of a 



supposed cockroach discovered by Dr. Chas. Brongniart in the 



Middle Silurian of Jurques, Calvados, France, and named Falceo- 



hlattina Bouvillei. The Coal-measures of Commentry, AUier, 



