SAND-EELS. 
567 
I am. AMMODYTIDfE. 
Body elongated , fusiform , terete or compressed, covered with thin cycloid scales or partly naked. Caudal fin 
separated from the other vertical fins. Jaws without teeth*. G'dl-openings large: branchiostegal membranes more 
or less completely free from each other and from the isthmus. Pseudohranchice well- dev eloped and distinct. 
Air-bladder wanting. Pyloric appendages rudimentary . 
The place of this family in the system has long 
been a debated question. The original opinion of mo- 
dern systematists, that of Aetedi, was that the Sand- 
Eels — with their long dorsal tin occupying the greater 
part of the back — should be ranged beside the genus 
Coryphcena. This opinion, borne out by the Mackerel- 
like coloration of the Sand-Eels, still survived in 1839 
in Swainson b , who pointed out the external resemblances 
between these fishes and Lepidopus. Linnjeus had ima- 
gined that he had made an improvement by uniting 
all fishes without ventral fins into an order ( Apodes ), 
and thus in 1817 — 1829 the Sand-Eels assumed in 
Cuvier’s works" the rank of a genus within the family 
of the Eels, and in 1832 — 1841, in Bonaparte**, that 
of a subfamily ( Ammodytini ) of the Ophidiidce among 
Malacopterygii apodes. When MulleiC formed the order 
Anacanthini , he did not hesitate to include in this or- 
der the family Ophidiidce , but he declared himself 
unable to give a decided opinion as to the place of 
Ammodytes, though he positively denied the relationship 
between this genus and the Eels. In his later work 7 , 
however, Bonaparte ranged the Sand-Eels, as a distinct 
family (Ammo dy tides), among the Gadi, and Gunther 0, 
did not hesitate to include these fishes among the 
Anacanthini as a subfamily (Ammodytina) of the Ophi- 
diidce. 
This diversity of opinion has been caused by the 
absence in the Sand-Eels both of the ventral fins and the 
air-bladder. The reduction and eventual disappearance 
of the ventral fins is a characteristic which, as we have 
seen above, may occur within several piscine orders. 
The absence of the air-bladder may be explained in 
the same way. We must, therefore, look to other 
characters in order to discover the nearest relations of 
the family, and as often happens in such cases, we may 
have recourse to characters apparently of minor im- 
portance. The Sand-Eels are approximated by their 
form and coloration not only to the Mackerels but, 
still more closely, to the Garpikes. To the latter fishes, 
which are Pharyngognate Anacanthini, it is impossible 
to unite the Sand-Eels, in which the lower pharyngeals 
are free from each other. Still, where the lateral line 
lies in the Garpikes and Elying-fishes, along the ventral 
margin, at the boundary between the sides and the 
belly, and also along the base of the anal fin, here we 
find in the Sand-Eels a dermal ridge, somewhat raised 
in the same way. The physiological signification of 
this ridge is indeed unknown, but in a morphological 
respect it shows at least a trace of resemblance to the 
Garpikes and Flying-fishes, such a resemblance as we 
have seen above in other Anacanthini, in the Couchia- 
stage of Onos. The Garpike-like coloration of these 
last fishes, in its sharp contrast to that of adult Rock- 
lings, may also be a trace of their original relationship 
to the Sand-Eels. Among the osteological peculiarities 
which we have above remarked in the Gadoid family, 
a Day ( Fishes of India, p. 420) observed, however, “a few, fine teeth opposite the symphysis in either jaw” in Ammodytes ( Blee - 
keria ) kallolepis. 
b Nat. Hist. Fish., Amplu, Rept., vol. II, p. 254. 
c R'egne Animal , tome II, ed. 1, p. 240; ed. 2, p. 360. 
d Iconogr. Fn. Ital., tom. Ill, Pesci , Introd., p. 15. 
e Abh. Akad. Wiss. Berk 1844, p. 177. 
I Uatalogo Metodico dei Pesci Europei , Napoli 1846, pp. 6 and 40. 
g Cat. Brit. Mus., Fisli, vol. IV, p. 384. 
72 
Scandinavian Fishes. 
