TERMS USED 



Abd. I, Abd. II, &c. An abbreviated expression of "first abdominal 



segment," "second abdominal segment," &c. 

 Anal horns. (Analdornen). Small horns borne dorsally on the most 



caudal abdominal segment. 

 Anal organs. The two modified hairs arising from a tubercle ventro- 



cephalad of the anus, and usually curving caudo-dorsad. 

 Anal papilla or tubercle. The tubercle bearing the anal organs. 

 Ant. I, Ant. II, &c. An abbreviated expression of "first segment of 



the antenna," "second segment of the antenna," &c., the number- 

 ing of the segments beginning with the proximal (basal) segment. 

 Antennal organs. Sense organs borne usually, when present, on the 



distal segment of the antennae. 

 Clavate (tenent) hairs. Hairs with swollen or clubbed ends, borne 



most commonly on the tip of the tibia. 

 Claws. Inferior or inner clawe — the smaller claw of the collembolan 



foot, absent in some of the lower genera. 



Superior claw or outer claw — the larger of the two claws borne by 



the tarsus. 



Oentes. The second or middle part of the furcula, consisting of two 

 separate parallel pieces which proceed from the distal end of the 

 manubrium, and bear at their own distal ends the two mucrones. 



Furcula (saltatory appendage, spring). The organ borne by the fourth 

 or fifth abdominal segment and used for leaping. The furcula is 

 considered to be in normal position when lying along the ventral 

 side of the body and pointed cephalad, and its dorsal and ventral 

 sides are considered as taken in this position. As a matter of con- 

 venience, the drawings are often made .with furcula extended, in 

 which the ventral side turns dorsad and vice versa. 



■Genital papilla. A papilla noticeable in the Sminthuridse upon which 



opens the genital aperture. 

 Length is reckoned from the most cephalic part of the head when held 



in natural position, to the caudal end of the abdomen, not to the 



tip of the extended furcula. 

 Manubrium. The basal piece of the furcula, joined by its proximal end 



to the abdomen and at its distal end to the two dentes. 

 Mucrones. The two small end pieces of the furcula proceeding from 



the two dentes. 



Post-antennal organs. Oblong or elliptical organs situated just caudad 

 to the bases of the antennae. 



Tenaculum or catch. A small organ which holds the furcula in posi- 

 tion under the abdomen when at rest. 



Th. I, Th. II, &c. An abbreviated expression of "first thoracic seg- 

 ment," "second thoracic segment," &:c. 



Ventral tube. A tube or tubercle proceeding from the ventral side of 

 the first (anterior) abdominal segment. 



