163 Mr. J. Lubbock on two new species 0/ Calauidse. 



Darwinii, P.Bairdii and M.grandis, and a simple one in A. Pater- 

 sonii. It is also provided with a dentated plate in L. Patago- 

 niensis and magna, with a spine (analogous to a plate) in M. 

 grandis and A. Patersonii; and perhaps a part of the large ante- 

 rior plate of L. Darwinii and P. Bairdii, which rises from the 

 next segment, may be considered to belong to this. 



The sixth has a lanceolate hair in L. Darwinii and P. Bairdii 

 only, and bears a dentate plate in every species except L. Pata- 

 goniensis. 



The seventh has a dentate plate in every species, and with the 

 preceding forms the most important part of the prehensile ap- 

 paratus, the teeth being turned in such a direction as to retain 

 firmly any object seized. 



The eighth has two hairs, one lanceolate and the other gene- 

 rally ringed, but sometimes simple, and also either a dentated 

 plate, as in L. Paiagonietisis and magna, M.grandis and A. Pater- 

 sonii, or a spine as in L. Danvinii and P. Bairdii. This is the 

 first segment of the swollen portion, which includes the ninth, 

 tenth, eleventh, twelfth and thirteenth. 



The ninth bears a lanceolate hair in every species except A. 

 Patersonii ; and two large, generally wrinkled hairs, one of which 

 however in M. grandis, and both in A. Patersonii, are simple. 



The tenth a lanceolate and two others, which in L. Dar- 

 tvinii and P. Bairdii are one wrinkled and one plumose, and in 

 L. Patagoniensis and M. grandis one wrinkled and one simple ; 

 in L. magna both wrinkled, and in A. Patersonii both simple. 



The eleventh has a lanceolate hair ; a prehensile spine, which 

 in L. Darwinii and P. Bairdii is represented by a large ringed 

 hair ; and a third which is simple in M.grandis and A. Patersonii, 

 wanting in P. Bairdii, and wrinkled in the other three species. 

 It is evident therefore, as I have remarked above, that the pre- 

 hensile spine, which is large in L. magna, is no new organ, but 

 merely a hair very much developed. 



Finally, the twelfth has, like the preceding segments, a lanceo- 

 late hair, and two others which are either wrinkled or simple, or 

 in M. grandis plumose. 



The remaining joints are so indistinct, and it is often so dif- 

 ficult to determine to which the hairs belong, that I did not 

 think it worth while to examine them as carefully. It is how- 

 ever evident that the hairs are arranged according to the same 

 plan, the chief difference being, that whilst the lanceolate remain 

 unaltered, the wrinkled and simple have been replaced by plu- 

 mose hairs. The same regularity in the number, structure and 

 arrangement of the hairs is also found on the other organs, and 

 the more they ai-e examined, the more does this become appa- 

 rent. I hope I shall not be considered to have described the 



