some rare Crustacsa. 493 



parasites des Echinodermes " *, had described under the name 

 of Synaiiphilus luteus a Copepod parasite which appears to 

 be identical with the form we have recorded from Loch Linnhe; 

 and as MM. Canu and Cuenot's memoir was published in 

 ] 892, Remigulus tridens necessarily becomes a synonym of 

 Synatiphilus luteus^ Canu and Cuenot. 



Diaptomus lacimatus, Lilljeborg. (PI. XII. fig. 1.) 



A freshwater Copepod from Loch Doon, Ayrshire, new to 

 Britain. 



This species of Diaptomus is readily distinguished from 

 any other member of the genus in the British fauna by the 

 peculiar form of the last two thoracic segments in the female, 

 as well as by the difference in the structure of the fifth pair 

 of thoracic feet in both sexes. 



Figure 1 (PL XII.) represents a female specimen seen from 

 above, and shows the peculiar form of the last two thoracic 

 segments referred to ; this specimen measured 1*8 millira. 

 (j^ of an inch) in length. MM. Jules de Guerne and Jules 

 Richard, in their revision of the freshwater Calanidge, when 

 referring to the characteristic form of the last two thoracic 

 segments in Diaptomus luciniatus, say : — " Ce Diaptomus se 

 distingue au premier coup d'oeil de tous les autres par la 

 forme des deux derniers segments thoraciques." 



This Copepod occurred very sparinglj' in the gathering 

 from Loch Doon, while another species of the same genus — 

 1). gracilis^ G. O. Sars — was of frequent occurrence. There 

 does not appear to be any previous British record of D. lacini- 

 atus, but on the continent it has been found at Kola in 

 Russian Lapland and in the vicinity of Bergen in Norway. 

 Prof. Cleve (of Upsala, Sweden) has also collected it in 

 abundance in the Lake of Geneva f- The altitude of Loch 

 Doon is between 600 and 700 feet above the sea. 



Lathonura rectirostris^ Lilljeborg. 



From Loch Doon, Ayrshire; new to Scotland. 



In the gathering of Entomostraca from Loch Doon there 

 were, besides Diaptomus laciniatus, already referred to, 

 several other species of more or less interest, most of which 

 have, however, been recorded from other parts of Scotland ; 



* Revue Biol, du Nord de la France (Oct. 1892), p. 19, pi. i, figs. 6 

 and 7. 



t " Revision des Calanides d'eau douce," by Jules de Guerne and Jules 

 Richard, p. 47, separate copy (1887). 



