108 



SYNOPTICAL 

 II. ARTICU- 



ARTICULATA. I 



CIRRHOPODA, 



OR 



MOLLUSCA ARTI- 

 CULATA. 



A link between the 

 two orders, including 

 barnacles. 



DIGESTION. 



Simple intestinal 

 canal, terminating at 

 the base of a long 

 tube. A liver is pre 

 sent. 



ABSORPTION 



of Chyle. 

 By ordinary veins, 



AERATION 



of the Blood. 

 Branchiae attached 

 to the base of the legs . 



ANNELIDA. 



Serpulse, marine 

 worms inhabiting 

 tubes of sand, &c. ; 

 and earth worms. 



INSECTA.* 

 In the larva state 

 vermiform, like an- 

 nelida in the perfect 

 imago state, furnished 

 with wings, except the 

 aptera, (centipedes) 

 including hemiptera, 

 (aphides) orthoptera, 

 (grasshoppers) cole- 

 optera, (beetles) neu- 

 roptera, (dragon flies) 

 hymenoptera, (bees) 

 lepidoptera, (butter- 

 flies) diptera, (com- 

 mon flies.) 



Intestinal canal, 

 sometimes a simple 

 tube ; sometimes di 

 lated into many 

 pouches. No liver 



Same as last divi- 

 sion. 



Branchiae, some- 

 times placed at one 

 extremity of the body, 

 sometimes distributed 

 through its length, in- 

 teriorly or exteriorly ; 

 in some genera so 

 obscure as to escape 

 observation. 



(Esophagus often 

 dilated into a crop, 

 and having at its low- 

 er part a gizzard for 

 triturating the food. 

 The stomach very 

 large in the larva 

 state, reduced in the 

 imago. Hepatic vessels 

 opening into the low- 

 er portion ; perform 

 the functions of liver. 

 Small intestines most 

 developed in the im 

 ago state, when the 

 stomach is reduced 



The chyle appears 

 simply to transude 

 from the intestines 

 into the general pores 

 of the surrounding 

 parts, where the fluids 

 undergo a diflused 

 circulation. 



ARACHNIDA. 

 Spiders, scorpions. 



As in insecta. 



CRUSTACEA. 



As in insecta. 



Numerous tracheae 

 opening in external 

 orifices and ramifying 

 internally, pervade 

 the body, and thus 

 convey air through- 

 out the difiiised cir- 

 culation. 



A double series of 

 pulmonary cavities, 

 covered with ramify- 

 ing blood vessels, four 

 on each side of the 

 dorsal vesssel. 



Stomach sometimes 

 as in lobster, furnish- 

 ed with an apparatus 

 for trituration, con- 

 sisting of calcareous 

 lines in a cartilagin- 

 ous fi-ame-work ; an 

 ample liver. 



By ordinary veins. 



Branchiae attached 

 to the base of the legs. 



* In insecta (here are generally Ihirteen segments; 1. the head; 2. carrying the fore legii ; 3. 

 carrying wing* and legs. Tliese "three constitute the thorax, the remaining nine the abdomen. 



