234 Putft III. — Eleventh Annual Report 



Genus Peracantha, Baird. 



Peracantha truncata (M tiller). 



1781. Lynceus truncatus, Miiller, Entom., p. 75, PL II. figs. 4-6. 

 1850. Peracantha truncata, Baird, Brit. Entom., p. 136, PI. XVI. 

 f>. I. 



This also was one of the rarer species, and, like the two previous forms, 

 was only obtained in the gatherings of bottom material. 



Genus Leptorhynchus, Herrick. 



Leptorhynchus falcatus (G. 0. Sars). (PL VII. fig. 30.) 



1861. Alona falcata, G. O. Sars, op. cit., p. 20. 



1862. Harporliynchus falcatus, idem, ibidem, Andet. Bidrag., 

 p. 41. 



1884. Leptorhynchus falcatus, Herrick, Crust, of Minnesota, p. 111. 



The long slender curved beak of this species (fig. 30) enables it *o be 

 readily distinguishable. It was of frequent occurrence in the bottom 

 material only ; both males and females were obtained. The beak of 

 Leptorhynchus falcatus is said to exceed in length that of any known 

 species of Lyncied. Norman and Brady* record it from 'Sweet-hope 

 and Green Lee Lochs, Northumberland ; Lochend Loch, Kirkcudbright- 

 shire ; and Lochmaben Castle Loch, Dumfriesshire ; ' and add, in ' all these 

 localities it was numerically scarce.' 



Genus Chyclorus, Leach (1816). 



Chydqrus sph&ricus (Miiller). 



1776. Lynceus sphsericus, Miiller, Zool. Dan. Prod., .No. 2932. 

 1816. Chydorus millleri, Leach, Encyclop. Brit., Supp. Art. 

 Annulosa. 



1863. Clufdorus sphsericus, Baird, Ann. and Mag. Nat. Hist., vol. 

 ii. p.' 89, t. 2, figs. 11-13. 



Frequent, and only in gatherings of bottom material, both from the 

 head of the loch and from Brinacory. 



GYMNOMERA. 



Family Polyphemidte, Baird, 1845. 



Genus polyphemus, Miiller. 



Polyphemus pediculus (Linne). 



1746. J\[onoculus pediculus, Linne, Taun. Suec, No. 2048. 



1776. Polyphemus ocidus, Miiller, op. cit., No. 2417. 



1850. Poli/phemus pediculus, Baird, Brit. Entom., p. iii. t. xvii., 



fig. I-' 



Taken in abundance with the tow-net, near the surface of the water, all 

 over the portion of the loch examined. 



G enus Bythotrephes. 



Bythotrephes longimanus, Leydig. 



This species was frequent in the surface tow-net gatherings ; it was alsc 

 * A Mon. of the Brit. Bosmin,, Maeroth., and Lynceidee, p. 80. 



