130 MR. W. L. SCLATER ON [Feb. 1, 



two thirds as long as the eye ; in a Sprat 3.5, also two thirds as long 

 as the orbit ; and in a Pilchard 71, longer than the eye. Thus these 

 appendages in number in the hybrid (61) were less than in the 

 Pilchard (71), but more than in the Herring(48) or in the Sprat (35) ; 

 while their length did not quite equal tliat of a normal Pilchard. 

 As to the character of these gill-rakers in the Pilchard, Sprat, and 

 Herring : in the first the lateral denticulations are very minute, a little 

 larger in the Sprat, and largest in tlie Herring ; to which last those 

 in the hybrid had the greatest affinity. Fins. — In the hybrid the 

 distance from the end of the snout to the commencement of the 

 dorsal fin was 3*4 inches, the entire extent of the base of the fin being 

 inserted midway between the snout and the root of the caudal fin ; 

 lower lobe of the caudal the longer ; anal rays almost hidden by the 

 scales. Scales. — The number of scutes 22 before and 14 behind the 

 base of the ventral fin ; they are weak. As regards the scale3, two 

 large rows exist just behind the head on the left side, and the 

 remainder resemble to a great extent those of the Herring, but with 

 the semicircular striae of the Pilchard. The scales on the right side 

 are similar to those normally seen in the Pilchard. The number of 

 scales along the body in Pilchards is from 29 to 30, in about 8 

 vertical rows, 17-18 scutes before the ventral fin and 14 behind it; 

 in the Sprat 47 scales along the body in 13 rows, 21-23 strong scutes 

 before the ventral fin and 11-12 behind it; in the Herring the 

 numbers of rows of scales along the body vary from .53-60, and there 

 are 13 scutes behind the ventral fin. Colours. — On the left side was 

 seen the beautiful purplish-golden hues of the Herring, but on the 

 right side were the silvery colours of the Pilchard. 



Salmo purpuratus. 



This specimen, which is 8*5 inches long, died at South Kensington 

 in August 1885. It was one of the fishes raised from the eggs brought 

 over from Canada by Mr. Wilmot in 1883, which were described in 

 the Society's 'Proceedings' for 1884, p. 24. Originally imported 

 as supposed eggs of the Salmon, the edge of the adipose dorsal fin 

 in the fry showed the orange tints of a Trout, while the par-bands 

 were from 7 to 10 and averaged 85. It is interesting, because spe- 

 cimens have been turned into the Thames, and were asserted to be 

 Land-locked Salmon, which is an error of identification. 



10. Notes on the Peripatus of British Guiana. 

 By W. L. Sclater, B.A., F.Z.S. 



[Eeceived January 31, 1887.] 



During my recent stay in Demerara I was fortunate enough to 

 procure a considerable number of specimens of a species of Peripatus. 

 This singular form was first discovered in British Guiana by Mr. im 

 Thurn, who sent examples home to Prof. Moseley. But the bottle 

 containing the specimens was broken before arriving in England, and 



