90 Mr. F. P. Cambii(lo-e— ^owe 



that, in the case of Clerck, the International Rules have 

 upset thirty or forty names concerning which an absolute 

 unanimity has prevailed amongst authors for quite a century. 

 If we are to swallow this camel, I for one shall not strain at 

 the change of a name or so where necessary in the cause of 

 consistency. 



I might also point out that in other branches of zoology — 

 Aves, Lepidoptera, Coleoptera, &c. — I cannot now recognize 

 by name many of the oldest friends of my youth. But if 

 the change has been necessary in these casos^ there is no 

 reason to object to necessary changes in the case of much less 

 popular groups, such as the Araneaj. 



llie Value of a Definite Type Species. 



On the last page of his paper Dr. Dahl says that he con- 

 siders that the fixation of a type would be of slight practical 

 utility, and he adds : — " So far as I can see, I can distinguish 

 three cases in which the type comes into question: (1) I 

 entirely agree with the founder as to the extent of his genus ; 

 (2) I agree with a later author ; (3) I have my own view," 

 And Dahl asks me to point out when I consider that a practical 

 dithculty arises which would be avoided by the selection 

 of a type. 



I answer at once, in every case, namely tlie practical diffi- 

 culty of ascertaining what exactly is the view to begin with. 

 Dahl appears to misunderstand the question at issue. The 

 jyractical value of a selected type comes in hffore loe can form 

 any definite view or opinion as to the characters of a genus at 

 all, either to agree with or to differ from. We are dealing, 

 for instance, with Latreille's genus Lycosa, having before 

 us a number of specimens to classify, many of wiiich we may 

 consider might conveniently be denoted by different group 

 names. We do not wish, however, to coin a number of new 

 names before we have definitely determined that there are no 

 names available which would suit our purpose. We wish 

 for some definite criterion by which we may judge as to 

 which of our specimens belong to Lycosa, which to Tarentula, 

 Trochosa, Pardosa, Arctosa, Putamia, llogna, Diapontia, 

 Tricca, Alopecosa, Trochosina, Leama, &c. &c. This can 

 only be secured by fixing a single type species to each name. 

 We must determine the type species of Lycosa first; and of 

 this genus Dahl insists that we must wait for a future worker 

 to break it up before we can settle on the type, and this 

 worker must further make a new genus of the species under 

 Lycosa before his selection will be valid, and so too with all 

 otlier genera where ty[)es have not been cited. 



