42 



with the hairs in different sizes and different numbers; from three to six, but five is the 

 most common number. Lateral hairs in multiple tufts and some single strong hairs. 



Abdominal segments broad, almost equal, the first two a little shorter than 

 the others. Lateral hairs on the first segment with tufts in common arrangement. 

 Lateral comb consists of about twenty to twenty-five scales, arranged in rows, 

 covering a triangular area. The scales are spatulated, very broad with the median 

 thorn only a little longer than the two lateral ones. 



Sipho short; about two or two and a half times longer than broad, slightly 

 tapering at apex; a long pecten reaching over half the length of the sipho; all thorns 

 at line, the first and last without thorns, the middle with from one to three, very 

 feeble thorns. A tuft of five hairs between end of pecten and apex. Anal segment almost 

 isodiametric, ringed by a remarkably small plate. Dorsal tufts well developed with tw r o 

 long stiff spines. Ventral brush in the barred area with about twelve rays, each ray 

 carrying about eight to ten hairs; before the barred area a few free tufts. A lateral 

 tuft consisting of one single, strong hair. Anal gills extremely short, budshaped. 



Lateral tufts of labrum rather long, the inner part modified in comb-hairs, ar- 

 ranged as a crown round the palatum, which is bordered with long, soft hairs. 

 Mandibles quadrangular, elongate, spinose at base; two curved spines before a col- 

 lar and a row of strong spines (nine) from margin. Dentition five strong teeth and 

 before them a very long curved spine and a short dagger-like one; a remarkable 

 group of minute thorns at base; a few curved setae within and a row of long hairs 

 at base. Process below, distinctly furcate, with strong hairs at apices; a group of 

 hairs at base. Maxillae broader than long with rounded apex; divided by a suture, 

 furnished with two teeth-like processes. At apex a tuft of hairs and at the base of 

 the tuft one spine. The space between suture and margin covered with short hairs; 

 na spines from margin. Palpe well developed with three or four digits from apex: 

 Mentum high, triangular, no especially developed median tooth and from ten to 

 twelwe almost equally large, lateral teeth. 



The skin of the abdominal segments covered with transversal series of minute thorns. 



Colour greyish dark. 



Systematical remarks: STAGER (1838 p. 554) has only found this species 

 on the shores of the island Amager near Copenhagen. He states that it is "not rare" 

 in the months of June and September; in August he has found the larva in 

 countless numbers in small water reservoirs along the coast line of Amager. It was 

 described as C. dorsalis Meig. 



In 1917 HOWARD, DYAR and KNAB (p. 634) reported that they have had speci- 

 mens from the Zool. Museum in Copenhagen and compared them with the two 

 American species Aedts onondagensis and A. Curriei. These two species are identical 

 as imagines, but as larvae they differ from each other; the first-named species have 

 both pairs of dorsal head-hairs single, whereas in A. Curriei they are multiple; there are 

 also differences with regard to the structure of the skin and the anal gills. Moreover, 

 of the two American species, A. onondagensis breeds in brackish water along the 



