1022 



SCANDINAVIAN I'I.SHE8. 



1am. ANGUILLIDiE. 



(rill-slifs {hdifceu till- brdiichial ai-(ltvs) iridc: (/ill-opeiiiiit/s {in flic s/:iii) iridehi separutt'd. Heart situated jnfit 



behitid the lirancl/ial carities. Vertical fins u'eU-derelojjed and Cdifiiin/f round the tail. Pectoral fins present. 



Anal fin separated from the tip of the snout hy a distance of more than tiiice the lenr/th of the head. Posterior 



nostrils distant from the niart/iii of the upjicr lip. I'onf/ur n-ith free tip. 



Among GCntheh's Plat/jschistce some (the Si/napho- 

 hranchid(s) are characterized Ijy the downward removal 

 of the gill-openiiigs to^\■ards the ventral side and their 

 uiiiou. Others (the I'tjiiihraiichidce) arc marked by so 

 great a prolongation of the forepart of the bodv that 

 the heart is situated far behind tlie branchial cavit}'. 

 t >thers again (the Nemiclithtjidce) have the vent far ad- 

 \anced, close to the gill-openings or separated from 

 them b\- a distance less than the length of the head, 

 and the beginning of the anal fin just beliind this 

 point. In others (tlie Saccophari/i/f/ida'") the moutli 



and pharynx are developed into a monstrous, funnel- 

 shaped gorge, so large that it exceeds the abdominal 

 cavity in length. Another division (the Ophichtlujidce 

 and Myrida, the former with finless tip of the tail) 

 are distinguished by a singular do^vnward removal of 

 the nostrils, sometimes quite to the margins of the 

 ujjper lip. Some (the Murcenesocidm) are without free 

 tongue; others (the Heterocongridce) are similar in all 

 these respects to our common Eel, Imt destitute ot 

 pectoral tins. The rest compose the family that has 

 its most marked type in the 



Genus ANGUILLA. 



The slim II hodi/ furnished irith scales immersed in the skin. 



By this solitary character it is always possible to 

 recognise one of tlie so-called Fresh-irafer Eels'', all 

 otlier distinctions being far too inconstant to be im- 

 plicitly relied on. Another character, which is not 

 peculiar, however, to Anguilla, though within the Scan- 

 dinavian fauna it is sufficient to denote the genus, and 

 besides has the advantage of being more conspicuous, 

 consists in the fact that the tip of tlie snout falls short 

 of the point of the lower ja^\■, or at least does not 

 project beyond it. 



"An infinite number of species," says GCnthek, 

 "ha\e Ijeen desci'ibed; but nujst are so badly charac- 



terized, or founded on individual or ?;o trivial cha- 

 racters, that the majority of ichthyologists will reject 

 them." Kali-', who was tlie greatest authorit)' on 

 this head until GCntheh's time, adopted no less than 

 49 species; GuNniKR'' reduced the number to 23. Da- 

 rkste" acknowledged only 4 or possibly 5. As Gi'N- 

 THEK has remarked'^, the genus is known throughout 

 the Tropical and Temperate Zones, with the excep- 

 tions of South America, the -west of North America, 

 and Western .Africa. In Scandinavia and tlie rest 

 of Europe only one species is recognised at the pre- 

 sent day. 



" For the Saccopharijiigido! see Gill and Ryder (Proc. U. S. N.it. Mus., vol. VI, p. 262; vol. VII, p. 48), wlio founded a separate 

 order {Lijomeri) to receive this family, and Vaillant {Exped. Scient. Travailleur, Talisman, Poissoiis, p. 193), wlio considered them to be as 

 nearly aUied to the Anacanthines as to the Enchelymorphs. Among thi-ir peculiarities it should first be remarked that the number of the 

 branchial arches is 5 instead of 4, the usual number in the Teleosts. 



' Fresh-water or at least brackish-water fishes indeed occur witliiu otlier Enclielymorpli genera, as in Gyiiinolhora.e, Pisoodoiiophs. 

 6'pltaijebyanchiis, Morinr/ua. and Mura-neso.r; but in these genera salt-water Eels predominate, and they are liesidcs entirely foreign to thi- 

 Scandinavian fauna. 



' Oatal. Apodal Fish., Brit. .l/»s. (18.50), p. 32. 



'' Cat. Brit. Mus., Fish., vol. VIII. p. 23. 



"" Arch. Zool. Experim., tome l\. p. 224. 



•'' Introd. Study of Fishes, p. 671. 



