Along the Essequebo and Potaro. 163 



and pe£toral fins is also generally a hard and strong 

 moveable spine ; while an adipose or fatty second dorsal 

 fin, of very variable form, is a common characteristic. 

 Among the Siluroids many of the largest freshwater 

 fishes are to be found. 



Lower down the river, at "The Croft," among the 

 rapids at Aretaka, where we landed and procured some 

 largt clumps of an Epidendron (E. bicornutum) , we saw 

 a thick part of a fish, known as the shanna or black lau- 

 lau, which must have been of some seven or eight feet 

 in length. The species was said to be of much the same 

 shape and size as the lau-lau, but with the skin marked 

 all over with large black spots. It would appear to be 

 either a Platystoma or Pimelodus, but there was no 

 possibility of fixing the identity of the species. 



Among the rapids just above Marihi, we were most 

 fortunate in obtaining a specimen of the native cormo- 

 rant (Phalacrocorax brasilianus), a bird which had 

 hitherto been unrepresented in the Museum, and which 

 is but rarely procurable. It is of a prevailing shiny 

 black colour, with greenish reflections, having very short 

 legs, and a long rather thin bill, suddenly hooked at 

 the tip, where it looks as though a small extra piece 

 had been added. 



This was the last good specimen procured, for although 

 next morning (Thursday, April 11th) we shot a young 

 specimen of the tree porcupine (Splii)i^urus prehensilis) 

 before reaching Bartica Grove, it was so covered with 

 sores as to be altogether unfit for preservation. 



The trip was at last over ! On the whole it was a very 

 successful one; for though several of the specimens that 

 I had expected to get, had not been procured, yet, on the 



X 2 



