354 AN EXPLANATION OF 



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

 men. 

 6QUAMULA,a Scale; an erect membrane placed between the thorax and 



abdomen. 

 Stem M ATA, the Ocelli or Httlc eyes placed on the summit of the head ; 



these are frequently considered in the character of a genus. 

 Sternl'm, the ridge running under the breast; this part is very con- 

 spicuous in the Di/tkicUc. 

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

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

 from the base to the apex of tlie elytra. 

 Obsolcta, indistinct, as if obliterated. 

 Striga, a narrow transverse line. 

 Sulcus, a deep hollow furrow. 

 SuTUPvA, tlie 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 species of the Coleoptera 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 ser\'es as sections of the Order ColeojAeru. 

 Tergum, the upper part or back of the abdomen. 

 Tessellata, spotted or marked with another colour chequerwise. 

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

 This part is subject to the greatest variety in sha])e, sculpture, &<•. 

 Many of the terms used to distinguish the elytra in Coleoptera are 

 also applicable to the thorax. 

 Aculcatus, furnished with sharp spines. 

 ^gualis, when of the same breadth with the elytra. 

 Angvhitus, the posterior margin having prominent angles. 

 Canuliculutus, with a deep longitudinal groove in the middle. 

 CarinatuSy the middle part of the disc raised into a straight longitu- 

 dinal ridge. 

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

 Cordatus, heart-shaped, the base notched, without angles. 

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



are pointed to neither extremity. 

 Crlstatus, the carinatcd ridge arched, dentated, and compressed. 

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

 Discus, the middle of the thorax, the line from i to c {fg. 4. pi. 10). 

 Gibbus, the disc elevated but not spherical. 

 Immarginutus, without clypeus or distinct rim. 

 In-ccqiiuHa, the surface not flat, but with irregular elevations and de- 

 pressions. 



