210 



PTILOTA : IMAGO — EXTERNAL ANATOMY. 



Variously fo 



cations of form will be serviceable to the beginner, who 

 would otherwise have to contend against a series of technical 

 names, which would be unintelligible to him, unless ac- 

 quainted with the Latin language, from which they are 

 generally derived. 



Filiform, when the an- 

 tennae are of equal 

 thickness throughout 

 their whole length, 

 like a thread (fig. (jy). 

 Setaceous, when they 

 insensibly diminish 

 in thickness to the 



tip (fig. 70). 



Moniliform, when they 



are formed of glo- 

 bular joints, resembling a necklace of pearls (fig. /I), 

 Cylindrical, when they are of equal thickness throughout, 



with the joints scarcely discernible. 

 Prismatic, when they resemble a prism, or are formed of 



three sides (fig. 72). 

 Easiform, angulated at the sides, large at the ])asc, but 



gradually terraiiuiting in a point, like a sword (fig. T-^)- 

 Subulated, short, and pointed at the tip. 

 Fusiform, narrowed at the two extremities, and thickened 



in the centre, like a spindle. 

 Aristate, when the antennae are terminated by a fine 



bristle (fig. 74). 

 Dentate, when the joints are armed with short spines 



(fig. 77). 



Serrate, when the joints are triangular, one of the angles 



being internally produced, like a saw (fig. 7^>). 

 Pectinated, when the joints are furnished with u long and 



