280 



SCANDINAVIAN FISHES. 



two northern species, we must have recourse to the 

 evanescent coloration, if it be necessary that the dijfer- 

 entia specijica shall embrace both sexes as well as the 

 younger specimens."' The attempt we have made in 

 the aliove diagnosis to range by side of the most con- 

 stant chromatic character the tenable characters of form, 

 is based on a comparison between six specimens of the 



preceding species and five of the species noAv under 

 consideration. With a moi'e abundant supply of ma- 

 terials for examination in the case of CaUionymits 

 maculatus, of which we have examined only one female, 

 we may find some exceptions to these characters, the 

 general validity of -which appears, however, from the 

 follomng table: 



Callionymus maculatus. 



OOM 



Lcngtli of the l)ody expressed in tnilliinetres __ 



Length of the head to the liind braiiehiostegti] margin in % of the length oi' the body 



„ ,. „ „ .. gill-opening ., ,. .. ,. ., „ „ „ -.- 



„ ,, ,, , .. ,, ,, „ ., Ijase of the anal liD... 



Base of llie anal liii in % of the length of the body 



Distance lietween I lie lirst dorsal fin and the tip of the snont in % of the length of the body 



Base of the anal liu in % of the distance between it and the tip of the snout 



Least depth of the tail in % of the base of the anal fin 



Breadth across the insertions of the ventral tins in % nf the base of the anal fin 



Length of the caudal fin in % of the distanee between the first dorsal fin and the tip of the snout 



Length of the snont in fo of the length of the body -- 



Longitudinal diameter of the eye in % of the length of the snont _ 



Breadth of the head across the preopcrcular spines in % of the length of the body 



Depth of the body at the insertion of the ventral fins ,, ,. ., ,. ., „ ,, 



Length of the 1st ray of the Isl dorsal fin „ „ „ „ ,, „ „ 



' 'ind 

 Base of the second dorsal fin ,, „ ., ,, „ ,, „ 



Length of the pectoral fins „ „ ,, ,, „ „ „ 



jj 5, ,) ventral ,. ,, ,, ,, ,, ,, ,, ,, 



Distance between the ventral fins and the tip of the snout ., „ „ „ ,, „ ,, 



xs 



CO 



Q 

 fll 

 22.9 

 17.2 

 62.5 

 27.5 

 24.6 

 70.0 

 ll.il 



■4(;.6 



83.3 



6.7 



97.6 



16.4 



0.8 



9.3 



15.4 



21.3 



18.5 



21.3 



18.S 



102 

 22.3 



16.7 



60.0 

 28.0 

 22.3 

 75.0 



12.3 



46.7 

 88.5 



6.8 



85.7 



16.7 



7.8 



24.8 

 23.4 

 26.5 

 17.1 



18.6 

 17.6 



146 



21.2 

 14.4 



54.4 

 26.4 

 20.2 

 80.4 

 12,4 



41.4 



117.8 



6.8 



80.0 



13.7 



7.5 



37.0 

 29.0 

 25.3 



18.8 

 19.4 

 16.6 



Callionymus lyra. 





H <L 



- p 



00 w 

 CO 



2 c n 



i=" 3 £. 



a. re 



2 P 



83 

 25.0 



18.9 



77.3 

 24.4 

 25.5 

 60.0 



15.7 

 51.7 



75.5 



7.8 



86.1 

 18.1 

 10.8 



10.2 



15.fi 

 26.1 

 17.8 

 2L4 

 18.0 



;r:i 3 9 



9 



168 

 26.8 

 20.2 

 83.0 

 24.4 

 27.1 

 60.4 

 16.0 

 56.0 

 72. f. 

 10.1 

 54.7 



19.6 

 9.5 

 9.2 



13.1 

 23.2 



19.0 



19.8 



20.0 



00 



& 



191 

 26.2 

 20.4 

 86.7 

 23.5 

 27.7 

 56.6 

 15.1 

 61.1 

 70.0 



9.6 



54.0 



17.8 

 9.4 



24.8 



13.8 



23.0 



16.3 



19.1 

 21.0 



237 

 28.9 

 23.2 

 94.1 

 25.0 

 27.5 

 60.8 

 13.0 

 54.2 

 78.4 



13,6 



43.8 

 18.1 



8.8 



60.8 

 14.0 

 24.0 

 16.0 

 19.0 



21.9 



Tiiis table also shows the most important changes 

 of growth and sexual differences. The most distinct 

 and remarkable instances of the former are expressed 

 ill the proportion between the length of the head to 

 the gill-opening and that of the bodA*. This proportion 

 sinks in CaU'wnymm maculatus, but rises in Call, lyra, 

 the two species thus shoeing different directions of 

 development, and being most closely allied during youth. 

 The sexual difference which appears in the distance be- 

 tween the ventral fins and the tip of the snout, and 

 which in Call, lyra is less in the female than in the 

 male, also seems to show tluit the female characters 

 have fixed tlic direction of development in Callionymus 

 maculatus, anrl tlic male characters in Call. lyra. This 



seems to be also the case with the average height of 

 the second dorsal fin, Avhich in Callionymus lyra is rela- 

 tively greater in the female than in the male (with the 

 exception of the last ray), and is generalh' greater in 

 Call, maculatus than in Call, lyra, though the females 

 of both si)ecies are much alike in this respect. 



With these exceptions we can find no remarkal)le 

 difference, in the form, tlie position of the parts of the 

 body, or the number of the fin-rays, between this spe- 

 cies and the Gemmeous Dragonet; and we may there- 

 fore refer tlic reader to the description of the latter 

 species. In the colour and the markings, however, there 

 appear considerable differences between the two species; 

 and it is l)v these characters that we may most easily 



