442 



HISTORY OF INSECTS. 



about till they die, may be considered as con- 

 stituting the FIRST CLASS of insects. All these, 

 the flea and the woodlouse only e-xcepted, are 

 produced from an egg; and when once they 



proofs of his devotion to the science, and of hi title to 

 the rank of the first entomological anatomist of the age. 

 Savigny, also, who sacrificed his sight to his anatomical 

 investigations, and was one of the savants who accompa- 

 nied the expedition to Egypt, has rendered the most im- 

 portant services to this branch of zoology, by his work on 

 the mouths of insects. In America, Melsheimer (who 

 furnished Knoch with the greater part of his species), 

 Say, Hentz, Le Conte, Harris, and many others, have 

 successfully exerted themselves in detecting and describ- 

 ing the insects of the United States. 



In the earlier writings of Lamarck, he included the 

 Crustacea, as well as the Arachnides, in his Class In- 

 secta. These have since been formed into separate 

 Classes by him, but as the latter of these is so nearly 

 allied to the true insects, we retain it at the head of that 

 Class, under its own proper title. 



ARACHNIDES. 



The Arachnides are oviparous animals, provided 

 with articulated members, but do not undergo a meta- 

 morphosis, similar to insects. They respire, either by 

 bronchiaj or by means of a trachea, the openings for 

 the admission of air being stigmatiform ; and they are 

 destitute of antennae. 



ORDER I. PULMONARI-ffi. 



With a heart ; each side of the abdomen with bron- 

 chial sacs ; six to eight eyes ; two pedipulpi ; two jaws 

 and palpi ; and four pair of feet : sexual organs double. 



SECTION I. PEDIPALPI. 



Very large palpi; abdomen distinctly annulated, hav- 

 ing no web-spinning papillae. 



FAMILY I. SCORPIONIDES. 



With a sessile abdomen, provided with four spiracles, 

 the six terminal segments forming a tail ; the last one 

 pointed, and serving as a sting, perforated for the pas- 

 sage of poison ; palpi forceps-shaped. Scorpio Afer, pi. 



FAMILY II. TARANTUL.E. 



With a pedimculated abdomen, each side below fur- 

 nished with two spiracles, and terminated by a stingless, 

 jointed filament ; palpi arm-shaped, with spinous ex- 

 tremities ; mandibles monodactyle ; anterior feet longer 

 than the others ; tongue long and dart-shaped. Thely- 

 phonus Caudatus, pi. 26. f. 2. 



SECTION II. ARANEIDES. 

 Palpi like small feet, ending in a hook ; last joint 

 bearing the sexual organs in the male ; four or six ma- 

 tt, illae placed near the anal opening, in both sexes, for 

 the purpose of spinning. 



I- TETRAPNEUMONES. 



Provided with two spiracles, and two pulmonary sacs 

 on both sides. Mygale Ceementaria, pi. 26. f. 3. 



II. DIPNEUMONES. 



Having only one spiracle, and one pulmonary sac, on 

 each side ; six spinning orifices ; the four exterior quad- 

 rangular, and two smaller ones in the middle. 



FAMILY I. TJJBITEI.A 



Spinning orifices fasciculated, approximated, and cy- 

 lindrical ; feet strong. Aranea Domestica, pi. 26, f. 4. 



FAMILY II. IN.EQUITELL.E. 

 Spinning papillae converging and conical ; feet very 



break the shell, they never suffer any further 

 change of form, but continue to grow larger 

 till they die. Thus the louse or the spider are 

 produced from an egg, never suffering any al- 



slender ; first and last pairs are usually longer than the 

 others ; jaws inclined upon the labium. Scytodes thora- 

 cica, pi. '26, f. 5. 



FAMILY III. ORBITEI.^. 



Differing from the preceding family, in the first and 

 second pair of feet being usually longest ; the jaws are 

 straight, and wider above. Epeira diadema, pi. 26, f. 6. 



FAMILY IV. LATERIGRAD.E. 



When in a state of repose the feet are horizontally ex- 

 tended, four anterior longest and nearly equal ; eyes 

 forming the segment of a circle in one division, and in 

 two parallel lines in another. T/iomisus castaneas, pi. 26, 



FAMILY V. CITIGRADJE. 



lar 

 their pr 



FAMILY VI. SALTIGRAD.E. 



Legs formed for leaping ; eyes either in a single or 

 double quadrangular group, the smaller ones within the 

 other. Eresus moniligerus, pi. 26, f. 9. 



ORDER II. TRACHEARIJE. 



Without a heart, but in its stead a single dorsal ves- 

 sel ; they respire through a radiated trachea, the air 

 passing through spiracles in the abdomen or thorax ; 

 eyes from two to four ; some are blind ; mouth usually 

 syphon-shaped ; sexual organs single. 



FAMILY I. PYCWOGONIDES. 



With a projecting syphon ; four eyes placed on a sin- 

 gle tubercle ; feet mostly long, terminated by unequal 

 hooks ; at the base of the first are two oviferous feet. 

 Pycnogomn Balcenarum, pi. 26, f. 1 0. 



FAMILY II. PSEUDOSCORPIONES. 



With very large, pediform palpi, with a didactyle 

 hand or a vascular button. Chelifir Cancroid, pi. 26, 



FAMILY III. PIIALANGITA. 



With slender filiform palpi, terminated by a hook 

 Siro rubens, pi. 26, f. 12. 



FAMILY IV. ACARIDES. 



With an oval or globular extremely minute body ; ge- 

 nerally with two filiform palpi ; eyes minute ; eight 

 hairy feet, each terminated with two or three hooks. 

 Trombidium tinctorum, pi. 26, f. 1 3. 



FAMILY V. HYDRACHNELL^E. 



Mouth generally produced and feet adapted for swim- 

 ming. Hydrachna ycngrapJiica, pi. 26, f. 14. 



FAMILY VI. 



Mouth produced, legs formed for walking, wanderinz, 

 parasitical land animals. Argus rvfiexus, pi. 26, f. 15. 



FAMILY VII. MICROPHTHIRA. 



Having six legs, and always parasitical. Leplits Au- 

 tumnalis. PI. 26, f. 15. 



INSECTS. 

 ORDER L THYSANOURA. 



These are apterous insects, with six feet, and under- 



