354 AN EXPLANATION OP 



Spiracula, the respiratory organs, situated on the sides of the abdo- 

 men. 

 SquamulajA Scale; an erect membrane placed between the thorax and 



abdomen. 

 Stemmata, the Ocelli or httle eyes placed on the summit of the head r 



these are frequently considered in the character of a genus. 

 Sterkitm, the ridge running under the breast; this part is very con- 

 spicuous in the Di/ticida. 

 Stigma, a spot or mark generally on the upper wing. 

 STRIA, a longitudinal line, and often punctured, generally extending 

 from the Ijase to the apex of the elytra. 

 Obsokta, indistinct, as if obliterated. 

 Striga, a narrow transverse line. 

 Sulcus, a deep hollow furrow. 

 SuTURA, the part where the elytra meet and form the line in the tnid- 



dle of the back, from the base to the apex. 

 Tarsus, the Foot. The form and number of the joints vary according 

 to the insect's mode of life: in several sjtecies of the Cokoptera the 

 anterior tarsi of the male are frequently broader than those of the 

 female, and consequently serve as a sexual distinction. The num- 

 ber of joints in the tarsi serves as sections of the Order Coleapterc. 

 Tergum, the upper part or back of the abdomen. 

 Tessellata, spotted or marked with another colour chequerwise. 

 THORAX, the part intermediate to the head and body. (Seep. 31.) 

 This part is subject to the greatest variety in shape, sculpture, &c. 

 Many oi" the terms used to distinguish the elytra in Cokoptera are 

 also applicable to the thorax. 

 Acideutus, furnished v/ith sharp spines. 

 j^ijualis, when of the same breadth with the elytra. 

 Angidatus, the posterior margin having prominent angles. 

 Canaiiculatus, with a deep longitudinal groove in the middle. 

 Carinatus, the middle part of the disc raised into a straight longitu- 

 dinal ridge. 

 Convexiis, when the surface is elevated like the section of a sphere. 

 Co7-datus, heart-shaped, the base notched, without angles. 

 Crciiutus, the margin notched, but in such a way that the incisures 



are pointed to neither extremity. 

 CrisUttiu, the carinated ridge arched, dentated, and compressed. 

 CucuUattis, the carinated ridge hollowed before into a kind of hood. 

 Discus, the middle of the thorax, the line from 6 to c {jig. 4. pi. lo). 

 Gibbus, the disc elevated but not spherical. 

 Inmiarglriafus, without clypeus or distinct rim. 

 ImtquaUii, the suri'ace not flat, but with irregular elevations and de- 

 pressions. 



