ON BOSMINID-E, MACROTHKICIDJE, ETC. 377 



the four or five spines nearest to the claws which rapidly increase 

 in size posteriorwards, and are long and slender, the last situated 

 round the supero-posteal angle ; terminal claws long and slender 

 with a well-developed spine springing from the base, and equal 

 in size to the largest (last) of the marginal spines. Length, -^-nd 

 of an inch. 



"We have only seen a single specimen of this interesting Lyn- 

 ceus, and from this the characters and figures here given are 

 taken. The peculiarity of the spiny armature of the abdomen 

 distinguish it at a glance from its congeners. The British speci- 

 men was taken by one of the authors (A. M. N.) in a small pond 

 near Morden Moor Farm, in the parish of Sedgefield.* On the 

 Continent it has been found near Berlin and in Norway. 



Gr. 0. Sars is of opinion that Midler's figures of Lynceus quacl- 

 rangularis are intended to represent this species. It may be so ; 

 the length of the abdomen, as drawn, seems rather to point to 

 tenuicaudis than to the more common form generally accepted as 

 quadrangularis ; but as we have stated in our notes on the latter 

 species, in a case of doubt like the present, where it is impossible 

 to decide, with anything approaching to certainty, which of seve- 

 ral allied species (then grouped under one name) was more imme- 

 diately intended by the author, it seems desirable to retain the 

 name for the more common species to which it has hitherto been 

 applied. 



5. Lynceus gtjadhangtjlaeis, Mailer. PI. XXI, fig. 5. 



1776. Lynceus quadrangular is, Miiller. Zool. Dan. Prod., p. 



199, No. 2393. 

 1843. Alona quadrangularis, Baird. Ann. and Mag, Eat. Hist. 



II, p. 92. PL III, figs. 9-11. 

 1860. Lynceus affinis, Leydig. Naturgeschichte der Daphniden, 



p. 223. PI. IX, figs. 68, 69. 



Carapace quadrangular, dorsal margin gently and regularly 

 arched, posterior margin somewhat truncate, but its angles both 



* A second locality is now known. Since the above has been in the printer's hands, A. 

 tenuicaudis has been found more abundantly in a pond at Welbourne, Lincolnshire, by 

 (i. S. B. 



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