1903.] ox ABNORMAL CLAWS IX THE CRAB AXU LOBSTER. 195 



near Lado, on the White Nile, which, by the owner's kind per- 

 mission, I exhibited at a meeting of this Society on Dec. 18th, 

 1900 (see P. Z. S. 1900, p. 949). Its identity had been previously 

 established by Mr. Thomas, who had recorded its occurrence in 

 'Nature' of Oct. 19th of that year ('Nature,' vol. Ixii. p. 599). 

 This skull is now, I am informed, in the Carnegie Museum at 

 Pittsburg, U.S.A. The horn of an example of the same species, 

 which I now exhibit, was obtained by my friend Capt. Claude 

 Hawker (Commander of the 10th Soudanese Battalion) from the 

 Belgian Officers at Lado in the autumn of 1902, and was taken 

 from a specimen unquestionably shot in that district, on the left 

 bank of the While Nile. The Belgians did not distingviish it 

 from the ordinary E. hicornis, and seemed to believe that all the 

 Rhinoceroses of that district belong to one species. 



"The present specimen is a front horn of R. simus, or, at any 

 rate, of a closely allied form. It agrees veiy well with the front 

 horn of the mounted specimen of R. simus in the gallery of the 

 British Museum, but is rather longer, measuring 31 inches in a 

 straight line from the base to the end. The front horn of R. simus 

 may always be distinguished from the corresponding horn of 

 R. bicornis by its broad, flattened surface at the base in front, 

 the basal front of this horn in R. hicornis being more or less 

 smooth and rounded and projecting in the centre. 



" Capt. Hawker has returned to the Soudan, and will probably 

 visit the southernmost station of the Anglo-Egyptian forces at 

 Mongalla, 15 miles north of Gondokoro, again this winter. I have 

 requested him to obtain further information about this Rhinoceros, 

 and have little doubt that he will do so." 



The Secretary exhibited a series of photographs of the Indian 

 Elephant in the act of congress, which had been presented to the 

 Society by Mr. H. Slade, of Rangoon, Burma. 



Mr. Henry Scherren, F.Z.S., exhibited some specimens of 

 the Edible Crab {Cancer pagurus) and the Lobster [Astacus 

 gam^narus) showing meristic variations, and made the following 

 remarks : — 



" Both these variations are in the left chela. That of the Crab 

 I received from Mr. Arthur Patterson of Yarmouth, in whose 

 name it will be handed over to the Bi-itish Museum (Natural 

 History). A process grows fi'om the lower edge of the palm, 

 resembling, though not very closely, the fixed and movable fingers. 

 It is, I suggest, a case of a rudimentary extra pair of fingers, 

 of which many examples have been figured by Bateson. The 

 valuation in the Lobster, also in the left chela, is more complex. 

 There is a process growing fi^om the vxpper edge of the mero- 

 podite, having three spines round the anterioi- margin, and a 

 soft, articular membrane arising therefrom. Beyond this is a 

 three-pointed process — a duplicate carpopodite, which must have 

 been movable in the living animal. On the noimal meropodite, 



13* 



