79 



tarsi and the tibiae are of equal length (21. pi. X, fig. 2g). The second of the two 

 tarsal joints is always the longer; Init their differences in length are not always 

 the same; in Ideoronciis Siaiuensis n. sp. f. inst. the tarsus II of the tirst pair of legs 

 is l.;5 longer than the tarsus I (Pi. I, ligs. 4h-i), while the former of these joints in 

 /. Mexicaniis Bks. is 2ä longer than the latter (21. pi. X, fig. Id). The tarsi hear 

 dorsally at the base of the basal joint a "tactile" hair and terminally on each side 

 of the claws a bifurcate or toothed hair. 



Halzan as well as Hansen saw in this subfamily a connecting link between 

 the two suborders; the latter of these two naturalists supported this point of view 

 from facts, principally taken from the structures of the antennae, while Balzan laid 

 greater stress on the structure of the legs and writes (1891. 12. p. 5(t2) "Je place 

 ma nouvelle famille entre les Olpium et les Obisiidae, parce qu'elle se rapproche 

 des Olpium, et s'éloigne un peu des Obisiidae par les femurs et les tibias des deux 

 premières paires de pattes courts et gros, tandis que dans les vrais Obisiidae, ils 

 sont plutôt longs et minces." Both authors are certainly right in their arguments 

 as well as in their conclusions, for according to the above we find in the structure 

 of the front margin of the céphalothorax, of the abdominal tergites, of the antennae, 

 coxae and legs features sometimes borrowed from the Obisiinae Dad. and sometimes 

 from the Garijpidne Hans. In a single character we find a similarity to the 

 Cblhoniidae, namely in the tactile hairs of the hand of the palps. 



II. Genera. 



Balzan subdivided his Pseudobisiidae Balz, into two subfamilies viz. the Pseiido- 

 bisiinae Balz, and the Microcreaginae Balz. (12. p. 502 and p. 548), the former having 

 a simple galea, an elongated céphalothorax and rather small antennae, the latter 

 significant by its distally divided galea, its quadrate céphalothorax and excessively 

 large antennae: the latter subfamily has also the front margin of the céphalothorax 

 prolonged into a large median tooth; these subfamilies were not accepted by Hansen. 

 Ellingsen has in a little paper (1901. 58. pp. 86 — 87) shown, that the first of 

 the characters of the Microcreaginae Balz, must necessarily be omitted, because 

 Ideoblothrus Strandi Elling, has a galea which is divided terminally. The other 

 characters seem too meagre for the foundation of a subfamily; those established 

 by Balzan must consistently go out. But the Microcreagris Balz. is nevertheless to 

 be regarded as a very good genus. 



The other genus Ideobisiuin Balz. was subdivided into three subgenera 

 according to the number of the eyes; Ideobisiuin Balz. has four eyes, Ideoroncus 

 Balz. has two eyes and Ideoblothrus Balz. has no eyes; minor differences are found 

 in the shape of the galea and the céphalothorax, the latter being rather elongate 

 in Ideoroncus Balz. while it is almost as broad as long in Ideobisiuin Balz. The 

 eyes certainly provide a good and practical character, and so sometimes do the 

 shape of the céphalothorax; but it will beyond a doubt be necessary to use a 

 number of characters to get a natural system. Ideoroncus pallidas Balz., /. Siamensis 



