240 



PTILOTA: IMAGO EXTERNAL ANATOMY. 



Vwiouilr funned i 



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. 69). 

 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. 71). 

 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). 

 Ensiform, angulated at the sides, large at the base, but 



gradually terminating in a point, like a sword (fig. 73). 

 Subulated, short, and pointed at the tip. 

 Fusiform, narrowed at the two extremities, and thicki-m-d 



in the centre, like a spindle. 

 Aristate, when the antenna* are terminated by a fine 



bristle (fig. 74). 

 Dentate, when the joints arc armed with short spines 



(fig. 77). 



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



being internally produced, like a saw (fig. 76). 

 Pectinated, when the joints are furnished with a long and 



