18 Elementary Manual of Zoology. 
mouth parts like those of the cockroach, but there is some doubt as to 
the manner in which the modification came about.! The proboscis is 
used for piercing the tissues of plants or animals and sucking up the 
juices upon which the Rynchota feed. Many of the species have cuta- 
neous glands, which secrete offensive matter. These glands pour out 
theic secretion by ducts which open on the meso and meta-thorax 
between the hind pair of limbs, Other species have glands which secrete 
wax, while others again have glands which secrete sugary matter. In 
the case of the wax and sugary secretion, the glands are situated on the 
dorsal surface of the abdomen. The following is a classified list of the 
more important groups of Indian Rhynchota :— 
I—Aprtsra.——Minute parasitic Rhynchota without wings at any 
stage of their existence. Include the lice, which are parasitic . 
on birds and mammals, 
I1.—Howortera,—Rbynchota with front wings of the same thick- 
ness throughout. 
(a) Coccide (Scale insects).—Tarsi one-jointed. Females usually 
scale. like. Male, with not more than one pair of wings. 
Mostly minute insects, e.g., Palm scale, coffee scale, tea 
scale, orange seale, lac insect and cochineal insect. 
(6) Aphida (Plant lice),.—Tarsi two-jointed. Antenne three to 
seven jointed. Minute insects, ¢.g., tea aphid, spruce 
Chermes, American blight. 
(c) Psyllide,—Tarsi two-jointed. Antenne nine or ten jointed. 
Hind legs often thickened for jumping, ¢g., Mango 
Psylla, and Indigo Psylla, 
({d) Cicadide.—Tarsi three-jointed. Three ocelli present. The 
males with sound-producing organs. Mostly large in- 
sects, ¢.g., the common “ croaker”’ of hill forests. 
(e) Fulgoride.—Tarsi three-jointed. Not more than two ocelli 
present. Antenne said to be inserted beneath the eyes. 
Include all the so-called Jantern flies, many of which are 
brilliantly coloured and of considerable size. One of the 
species (Phromnia marginella, Oliv.) produces large quan- 
tities.of a white sugary secretion, but the family is of little 
practical importance, 
(f) Cicadellida.—Tarsi three-jointed: Not more than two ocelli 
present. Antennz said to be inserted between the eyes, 
1 According to Professor J. B. Smith (Science, New York, April 1892), the whole beak 
consists of the fused blades of the maxille, the mandibles and Jabium being both rudi- 
mentary and the styles, contained within the beak, being merely modification of parts of the 
maxille. According to the older theory the mandibles and maxille form the styles, while 
the jointed sheath is compesed of parts of the labium (probably the fused labial yalps). 
