COTTOIDS. 



157 



is overgrown with scnwccd; hut some |icculiar loriiis 

 iiiake their way to the ahysses of the ocean, while 

 others have heeoiue iVesh-watei' (ishes, the former ( '^ ''//- 

 fniniihis) presenting a certain hkeness to Li/xais and 

 the latter (the sul)genus I'nuiitli'd) to dnhiiix. 



.loi;i)A\ and (iii,iii:i{T estimate the number of spe- 

 cies within this suhfamily at about 150, distributed 

 aiiKjng al)out 4(» genera and subgenera. Those genera 



which belong to the Scandinavian fauna, may be di- 

 stinguished as follows: 



.1.- Ono contiiiuous rlorsiil (in Genus CoUunciilii^. 



J)': Two fliftinct (ioi'sal (ins: 



1: Less than 20 niys in the anal (in: 

 a: Palatine bones toothless: 



«((.■ \ oiner toothless: Genus G/jmnocanthns. 



hh: ,, with teeth: „ Cottus. 



b: Palatine bones with teeth:. ,, CentriderniichtJiys. 

 2: More than 20 rays in the anal fin : ,, Trlfjlops. 



Genus COTTUNCULUS. 



\\c<ik, f/c.nhlr sjiiiiims rai/s. trrajiped in (t /(losc sl-iti, fonii tin' (Uitcri<n\ Imrrr /„i,i nf the rontinuous dorsal fin. 

 Skill irithont inir scales, hitf f/niitalafed or roitijli iritli smtdl sjiii/rs. Hind lurijc 7'lii' four prc'ojx-rndor spines 

 iilifiisi\ mid rnrrrcil irifli skin. Fine, cnrdiform teeth mi tin- loircr jnir. tin- inti'nnn.iillorij l/oiirs mid tlir romcr. 

 Jh-miilii(ist('(/iil iiiciidirmii's miitcd to flic lirand istlniiiis, irliidi is irithoiit miij trmisversc fold. Xo /jill-s/it Ijcliind 



flic foiirtli lirmicliiid arcJi. 



We assign the first place among the Scandinavian 

 Cottoids to this genus, which is without doubt the most 

 marked metamorphosis of tlie Cottoid type among the 

 forms of which we have to treat. It was first remarked 

 and characterized as a distinct genus by Collett in 

 1874. Its metamorphosis is connected, however, in 

 several respects with a retention oi the juvenile cha- 

 racters of the type. It is one of tliese characters that 

 most distinctly marks the genus, namely, the confluence 

 of the two dorsal fins, or, more strictly, their retention 

 of this condition. They are united in the same wax, 

 and with almost the same relations to each other in 

 respect of size, or at least of height, in the most de- 

 veloped young specimen of Cottus scorpiiis (tig. 44) 

 which AcASSiz has fisjured". 



Anothei- juvenile character may be found, as Col- 

 i.irn' has remarked, in the coloration of the Scandi- 

 navian species, with its 8hai-])lv defined, black, trans- 



verse bands on the head, body and fins. The clcse 

 pi-oximity of this genus to Cottus in other respects is 

 best shown by the typical ((]uadrangular) arrangement 

 of the parietal spines, the anterior pair of which are. 



Fig. 44. A yomio- specimen of (Jottiis ■■•■corjjiii.9, 1 1 '., iniii. in length. 

 Masrnilied. After A. AG.4SSIZ. 



however, .situated on the forehead in a line with the 

 hind margin of the eye. 



Three, ])erhaps four, species of this genus'' are 

 known to exist in the deep water in the north of the 

 Atlantic. ( hilv one of these species belongs to the 

 Scandinavian fauna. 



" Proe. Anier. Acad. Arts. So., vol. XVII, Vouiiy Of^seoiis Fi.^ftes, pi. II, tig. 2. Tlie same clianges of development in the mutual 

 relations of the two dorsal fins are shown in the result of Sindev.\i.l"s observations of the development of Cottiis gohio (Vet. Akad. Handl., 

 v(d. I 1855), Om fiskyiii/els itivecliiiig, p. 7, pi. I, figs. 3 and 4. 



'' Cotltis tfiomsoiiii Gthr, Proc. Roy. Soc. Edinb. vol. XI (l.Si^l — 82) p. 079. Vottnnculu.i torvus, Goode, Proc. U. S. Nat. Mus. 



1880, p. 479; Jonn.. Gu-n., Bull. U. S. Nat. Mus., No. 10, p. 088. 



