Thompson's midge. 119 



first sight called to mind the Ciliata glauca and Gadus ar- 

 genteolus ; but the great size of the ventral fins, which were 

 likewise of a pitchy blackness for nearly the last third of their 

 length, seemed opposed to their identity with these species. 

 The boatmen who accompanied me had not observed this fish 

 before, nor had they heard anything of it. 



'*The general form elongate; belly protuberant. On a close 

 examination of all the specimens, nine in number, no cirri can, 

 with a high power of lens or on the field of the microscope, 

 be detected on either jaw. The largest individual, ten and a 

 half lines in length, may be characterized as having the upi^er 

 jaw the longer; strong and pointed teeth in both jaws; head 

 occupying rather more than one fourth of the entire length; 

 eye equal in diameter to one third the length of the head; 

 opercle rounded at the base, altogether forming a portion of 

 a circle; first dorsal fin originating just over the opercle, so 

 sunken, and its rays (which are thick and blunt) so short, as 

 to be hardly distinguishable in the profile of the fish, not less 

 than twenty -five rays; second dorsal commencing close to the 

 first, and before the end of the pectorals, of unequal height, 

 extending to the base of the caudal, not less than fifty rays; 

 pectoral fins rather less than one fifth of the entire length, of 

 moderate size and rounded; placed very high, somewhat above 

 the opercle, about twenty rays; ventrals placed high, commencing 

 rather in advance of the pectorals, somewhat square at the end, 

 occupying one fourth of the entire length, reaching to the vent 

 and consisting of about six rays; anal fin commencing at the 

 vent and extending to the base of the caudal, unequal in. 

 height, having at least forty rays; caudal fin elongate, occupying 

 one fifth of the entire length — measured from the last vertebra 

 of the body, somewhat rounded at the end, containing about 

 thirty rays; branchial rays about seven; vent midway between 

 snout and base of the caudal fin. Colour, (when recent) back 

 rich green, varied with dots of gold and black; operculum, 

 entire sides, and under surface bright silver; pectoral, dorsal, 

 anal, and caudal fins uniformly of a pale colour; ventrals 

 likewise so for two thirds from the base, remainder pitch black; 

 irides silvery. 



"Since the above was written I have been favoured by Mr. 

 Yarrell with original specimens of Ciliata glauca, obtained 



