193 



1 with basal half white ; yellowish white spot on the mesonotum always present, 

 diamond shaped or elongate; tip of the abdomen terminating in a long style-like 

 process, little more than four times as long as thick ; dorsal abdominal segments 

 large with an obconical white spot at apex ; venter whitish ; legs never fimbriate 

 beneath; middle cox;e ontwardly at base with a small white spot never present in 

 male; hind femora distinctly longer than tibiae, tarsi (mly about half as long as 

 tibite, rarely a little longer. 



Larva $ (Fig. 19). — Length about 2"'"'. Differs from the imago in having spines 

 and processes of antenuse undeveloped, although relative proportions of joints are 

 about the same, joint 3 having 3 long hairs, but without specialized disc; 4 a little 

 dilated below at middle, where in a future stage issues the prong-like process of 

 imago : legs without fimbriae beneath ; anterior tibiae and tarsi being shorter com- 

 paratively and stouter than in either of the forms of the imago : abdomen much shorter 

 than thorax, margins dilated, dorsum concave, joints 8 and 9 conjoined and issuing 

 as a conical projection from an emargination in joint 7. 



Larva $ . — Differs from male larva in having antennae always slender, and the 

 joints without spines or processes, joint 3 only with several long hairs; abdomen 

 very short, joints 8 and 9 forming a long cone-like projection; hind legs a little 

 more slender than in male larva and in proportion to middle legs a little shorter ; rela- 

 tive length of the joints differing, tibiae much shorter than femora; tarsi somewhat 

 shorter than in $ ; whitish or yellowish spots less distinct. 



The following table will indicate the difference between Eheumato- 

 bates and Metrobates, to which it comes closest, as we stated in our 

 earlier article: 



Metrohates. 



General form oval obese, antennae $ 

 with the first joint very long and slender, 

 as long as the three following united, or 

 about as long as the front femur ; second 

 joint longer than the third. 



$ antennae slender, the first joint very 

 long, subclavate, a little longer than the 

 three following united, fimbriate beneath ; 

 second joint nearly as long as the two 

 following united; joints 2 and 3 thick- 

 ened at tip with a small tuft of bristles 

 beneath. 



Legs simple, normal, with no fimbria 

 beneath. 



Rheumatohates. 



General form elongate, subovate, an- 

 tennae $ with the first joint short, scarcely 

 one-third the length of the front femur ; 

 second joint very short, about one-third 

 the length of the third. 



(? antennae stout, the first joint much 

 swollen, shorter than the three following 

 united, with a stout strong spine beneath 

 near the middle ; second joint very short, 

 only about twice as long as thick, in fully 

 formed $ with a spine at base within ; 

 third joint longer than the fourth, curved 

 and thickened at tip, with a large disc 

 beneath and a spine; fourth joint with a 

 prong-like process. 



Legs in $ with middle femora and 

 tibiae strongly fimbriate, the hind femora 

 strongly curved in abnormal form, etc. 



The peculiar disc-like organ or enlargement of the short antennal 

 joint near the apex below exists only in the male sex. It varies in size 

 with the age of the individual. In the very young larva, it is not pres- 

 ent and there is only a slight thickening of this portion of the joint. 

 In the older larva it is present in a more or less rudimentary form and 

 attains its highest development in the adult. It consists of a broaden- 

 ing of the under surface of the joint, the face assuming a Avhitish mem- 

 branous appearance, slightly concave, with a slight ridge at the mar- 



