262 Rev. Canon A. M. Norman on British Mjsidae. 



times as long as peduncle of antennules, ciliated all round 

 right down to the base of outer margin ; a long very narrow- 

 second joint, which is furnished with two setee on each side 

 and terminates in an acute spine-like point. Legs having 

 tarsus longer than the preceding joint, of six articulations in 

 the earlier pairs and of eight in the last ; nail slender. Telson 

 rather more than twice as long as the breadth at the basCj in 

 the form of an elongated triangle, gradually attenuating, but 

 with flexuous side to the extremity, which is very narrow, 

 abruptly truncated, and entire, bearing four spines, the outer 

 pair of large size and the pair between them of about half 

 their length ; sides of telson with 20-25 spines, most crowded 

 towards the base and becoming more widely separated distally. 

 Inner uropods having a group of densely packed spicules 

 situated on the inner margin just below the large otolith ; 

 these spines occupy about one fourth of the total length of the 

 margin. Third pleopods of male similar to those of female. 



Kab. Found all round our coast in brackish water at 

 mouths of rivers, estuaries, salt-marshes, and such like 

 places ; but it seems to require more saline ingredients in the 

 water than does Palcemoyietes varians^ Leach, which latter 

 species is often found living in water in which no trace of 

 salt is perceptible and which is occupied by an otherwise 

 freshwater fauna and flora. 



Mr. A. 0. Walker tells me that about one out of every three 

 specimens received by him from the little river Alt, which is 

 a short way north of the Mersey, was more or less abnormal 

 in the spination of, and in some cases in the form of, the 

 telson. He adds that " a good deal of sewage runs down 

 the river," which may account for the irregular development. 

 These specimens had in some cases the two terminal small 

 spines replaced by spines of similar size to the outer pair. 

 This gave a totally different appearance to the end of the 

 telson, which now appeared narrowly rounded and beset with 

 equal-sized spines. I figure the abnormal terminations of 

 the telson in the case of two specimens which Mr. Walker 

 kindly gave me (PI. X. figs. 12, 13). 



Distrihution. Norwegian coast, from Christiania to Trond- 

 hjem {G. 0. Sars) ; Baltic {Lindstrom) ; Sweden [Lillje- 

 horg) ; Finland {Cajander) ; Denmark [Kroger) ; Holland 

 (P. P. C. Hoek) ; Belgium ( Van Beneden) ; Boulonnais, France 

 {Giard) ; Havre ; Concarneau (</. Bonnier) ; mouth of the 

 Seine {de Kerville) ; [Black Sea {Grebnitzkg) ?] ; White and 

 Murman Seas [Jarzynskg) *. 



* In Wagner (N.), ' Die Wirbellosen des weissen Mceres,' 1885, 

 p. 170. 



