Attempts at Classification. 77 



as to another character some other genus, is more distant from Phalangioidse than the other 

 genera are. The fact is that we are not acquainted with any other fixmily in which the 

 genera present differences from each other so great as in Ischyropsalidoid* ; we have therefore 

 given the characters for each of these genera, having had the good fortune to examine all 

 but one of them. We may add that we have discussed much between ourselves whether 

 it would be proper to divide Ischyropsalidoidse into a couple of families, but after a 

 prolonged consideration we arrived at the conviction that it would not be justified, inter alia 

 because it proved impossible to lay down the separating line in any place without violating 

 natural relationship. Perhaps some zoologist might in the future think of establishing nearly 

 every genus as the type of a family, but for just the same reasons we should dissuade every- 

 one from that attempt. 



After the printing of the present paper had begun we received from Professor F. Dahl 

 a treatise on a metamorphosis in the Troguloidae; the author urges that the genus Amo- 

 paum W. S. is an immature stage of animals belonging to the genus Dicranolasma W. S., 

 and Metopoctea Simon a juvenile form of Trogidus Latr. We consider this to be correct, 

 seeing that the rather few specimens of Amopaum and Metopoctea in the possession of our 

 Museum are immature animals. But we feel bound to add that Dahl has, on the other 

 hand, scarcely been fortunate in his synonymy for the species of Trogulus, which, as must 

 be admitted, are exceedingly difficult animals to deal with. Trogulus sinuosus W. S., which 

 according to Dahl is the third juvenile stage of T. nepoeformis Scop. (T. rostratus Latr.), 

 was in reality established on animals arrived at sexual maturity. Furthermore T. albicerus 

 W. S.' is too large an animal to be the first juvenile stage of T. nepwformis; from a state- 

 ment of Simon {b, p. 303) on the structure of the "chaperon" in "very young" specimens 

 of Trogulus we infer that Dahl probably did not possess such forms. 



Loman (g) has divided the Laniatores into two sub-orders : Insidiatores, established on the 

 family Triaenonychoidse, and Laniatores, comprising all remaining families. Above we proved 

 that one of his characters, viz. the existence of only two receptacula in Insidiatores but eight 

 in Laniatores, must be cancelled as incorrect. Only two features worth mentioning remain, 

 separating Insidiatores from Laniatores, namely, that in the former group penis contains a 

 muscle to the glans, while that muscle is absent in Laniatores (also in Oncopodoidae ?), and the 

 number of claws, the main character on which the family Triaenonychoidoe was originally based. 

 But in presence of the great conformity between the last-named family and the other Laniatores 

 these two differences together are, in our opinion, far from being important enough to justify 

 the establishment of the Trisenonychoidse as a separate (fourth) sub-order of Opiliones. 



' Originally this species was established because it examined this structural feature ; there is no distinct and not 

 possesses only one joint in each tarsus. We have again even any indistinct articulation of the tarsus. 



