On a large Silwoid from the Upper Amazons. 449 



diameter ? This is a point which it would be both important 

 and interesting to have confirmed by more detailed and special 

 observation. 



Lycosa ingens must indeed have great power ; it is the largest 

 known spider of the Tarantula group ; an adult female in my 

 own collection (from Porto Santo) measures 1| inch in length, 

 exclusive of the legs and palpi; the male, however, is much 

 smaller. If Mr. Pollock's example was an adult female, the 

 length of its body and that of the body of the lizard (ex- 

 clusive of the tail) would be about equal, so that the easy and 

 speedy demolition of the lizard need not excite surprise. 



Another observation of Mr. Pollock, and one upon which he 

 grounds a strong and (if sound) an interesting generalization, 

 is that each of the three islands of Madeira, Porto Santo, and 

 Deserta Grande has its " own peculiar large Lycosa^ no two 

 being alike; and (Mr. Pollock continues) it is a very remarkable 

 fact that these Lycosce vary in size inversely with the magni- 

 tude of the island in which they are found, — Madeira, the 

 largest island, having the smallest Lycosa, and Deserta Grande, 

 the smallest island, having by far the largest spider." It 

 would be important to know what were the range and extent 

 of the observations upon which this is stated ; the already 

 published facts respecting the localities frequented by Lycosa 

 ingens are certainly at variance with it. Mr. Blackwall states 

 (Ann. Nat. Hist., Sept. 1867) that he had received both sexes 

 of this species //"owi all three of those islands ; the same author 

 (Ann. Nat. Hist. ser. 2, xx. p. 284) also states that he had 

 received another almost equally large species, Lycosa tarantu- 

 loldes maderiana (Walck.), from Porto Santo ; and I have in 

 my collection examples of this same species from that island. 

 It would therefore surprise me very much to find that any 

 careful and at all extended search should confirm Mr. Pollock's 

 conclusion that these three islands, so apparently derived from 

 a common origin and so near to each other, should be yet so 

 capricious in respect of the distribution of their Lycosce. 

 Bloxworth, November 16, 1872. 



LXVI. — Notice of a large Siluroid from the Upper Amazons. 

 By Dr. Albeet Gunthee. 



The Trustees of the British Museum have recently purchased 

 a very large specimen of a Siluroid from the river Huallaga, 

 Upper Amazons ; it had been captured by B. La Meit, Esq., 

 who adopted the best method of preparing such large specimens, 

 by having it carefully skinned^ the fins and head remaining 

 intact and attached to the skin, and then packing it in spirits 



