M EXPLANATION OF ANATOMICAL PLATES. 



Fig. 20. CUws of Atihis : o, central filaments ; ss, membranous expansion of the terminal joint, ad- 

 vanced beneath the claws. 



Fin. 25, 86 : hhowing the upper and under side of the domestic cricket (Acheta arachnoidea). 



Fig. 27. Maxillary palpi (be) of the cricket ; b, galea. 



Fig. 28. Lower lip of the cricket ; a, mcntam ; d, labium ; e, additional articulations, divided into 

 two, three, or more lobes ; cc, apparently 3-jointed palpi, yet the basal joint enveloped or 

 concealed in the lip. 



Fig. 29. Mandibles of the grasshopper (Acrydium) : b, molar plate. 



Fig. SO. Mandibles of the cricket. 



Figs. 31, 32. Forms of antenna:. 



Fig. 88. Serrated antennw. 



Fig. 84. Lamelliform antennas. 



Fig. 36. Pectinated antcnnao; bipectinated, if it produces two long teeth, instead of one ; and flabol- 

 late, when the branches are very long, and flattened like the rays of a fan. 



Fig. 41. Setaceous antennae : filiform, when the antennae are of unequal thickness ; moniliform, as in 

 fig. 42 ; cnsiform, when tapering, and angulated at the sides ; subulate, when short, and 

 pointed at the lip ; fusiform, when narrowed at the two extremities and thickened in the 

 centre, as in fig. 43 ; clavate, when they gradually thicken at the top, as in 37 and 35 ; 

 geniculate, when bent as in 39 abc; capitate, when terminated in a knob or head, as 36 , 

 plumose, when the lateral filaments go off" from a shaft, like those of a feather ; nodose, 

 when the joints arc thickened in various parts like knobs ; verticillate, when whorls of hairs 

 arc placed at equal distances upon the joints ; fasciculate, when the hairs are gathered in 

 bundles upon each joint ; scopiferous, when a single bundle is placed upon one joint ; 

 palmate, when the antenna) are short, broad, and divided by deep divisions ; auriculate, 

 when one of the basal joints is dilated into a shield or car partially covering the rest ; 

 fissile, when they are terminated by a cleft knob ; ramose, when several of the joints throw 

 out branches ; furcate, when there are two branches like a fork ; aristatc, when the antennae 

 arc terminated by a fine bristle, as in the order Musca ; dentate, when the joints are armed 

 with short spines ; cylindrical, when they are of equal diameter throughout ; prismatic, 

 when they resemble a prism, or are fonncd of three sides. 



II. PARTS- OF THE DIGESTIVE APPARATUS.— PLATE B. 



Figs. 2, 3. a shows the esophagus, beginning in fig. 3 just behind the head, and terminating in an en- 

 largement which is the crop ; or, if the crop is absent, it terminates in the gizzard d. The 

 esophagus is a simple tube, except in the lepidoptcra. 



Fig. 4 c represents the position and relation of what has been denominated a sucking stomach. The 

 gizzard is shown in position, fig. 2 c. The true stomach, or, as called by some entomologists, 

 the chylific ventricle, is seen in figs. 2 & 3 e2 .- in this organ the food becomes semifluid or 

 pulpy, and remains until chylification takes place. The intestine begins as represented in 

 fig. 3, where the lateral tubes are inserted : it preserves a course more or loss contorted, as 

 is seen at /; and in some instances it is enlarged or inflated, as at g. The caecum is seen 

 »t g fig. 2, 



