neio Coccidse /row Mexico. 427 



Porococcus tinctoriuSy sp. n. 



9 . — Scales crowded on twigs, iTerwes-like, pitch-black, 

 hard, slightly shiny, 2^-3;^ raillim. diam., very convex, 

 globular, with the caudal end projecting like the neck of a 

 flask, with quite a large opening directed upwards. Some- 

 times there is a strong protuberance on each side of the 

 scale. 



? . — Placed in caustic potash, without boiling, gives at 

 once a dark cherry-red colour, blackish in thin solutions ; on 

 boiling it gives the most intense madder-colour, extremely 

 dark, stronger than cochineal. On adding HGl to the alka- 

 line solution it turns to a rather light claret-colour, and a 

 precipitate appears. After boiling pyriform, with a pale 

 purple tint, as though stained with logwood. Abdominal 

 segmentation rather obscure ; except the last four segments, 

 constituting a narrowed caudal portion, which are very 

 distinct and (especially the last two) brownish, becoming 

 chitinous. Dermis crowded with small round glands, some 

 simple, but most with three orifices close together, appearing 

 as one under a low power. Mouth-parts well developed. 

 Antennae and legs pale yellowish ; antennae 6-segmented, 

 formula 6 3 2 (5 1) 4 ; the sixth is quite long, like that of a 

 Dactylopiid. Tibia barely longer than tarsus ; claw large, 

 gently curved ; all the digitules filiform. Caudal tubercles 

 not much produced, each with a strong bristle ; anal ring 

 with six light brown, very long, and very stout bristles. The 

 tissue of the scale is invaded by the mycelium of a fungus, 

 and the female itself suffers from a dipterous parasite, Leucopis 

 or an allied form. 



Hah. Ameca, Mexico, June 7, 1897, on mistletoe on oak 

 {Koebele, 1748). Div. Ent. 7909. 



Porococcus Pergandei^ sp. n. 



$ . — Scales on twigs, 2 millim. long, of the same pitch- 

 black colour and hard texture as P. tinctorius, but shape 

 quite different. They are elevated, with a high longitudinal 

 crest, presenting three conspicuous nodular prominences, 

 which are sometimes deflected to one side ; in transverse 

 section the scale is triangular. Posteriorly the scale is not 

 produced, and the orifice is filled in with lamellse of brownish- 

 white secretion, arranged so as to resemble an aster-flower. 

 From the nodules of the crest there run blunt ridges down 

 the sides of the scale. The scales do not crowd together as 

 in P» tinctorius. 



