HdKEAL PKA1!L-Sini;. 



935 



All the lins are light and traiisparont, with only the 

 uiitc'ri<ir margin or, in the caudal fin, the two outer 

 I margins, of fli<' same colour as the liack, or dark. 



Ot' the internal organs we shall mereh' remark, 

 after Uay, that the stomach is cieeal, the dnodeiunn 

 furnished with 8 rather large pyloric appendages, and 

 the whole intestinal canal forms only two convolutions. 

 The testes and ovaries are paired and long. 



The Pearl-side is a gregarious fish, and tliough it 

 1 is most often met with in solitarj- specimens among 

 small Herrings (Sprats and Herring-fry), it also appears 

 in shoals of its own, instances of which have been ob- 

 served on tlie coasts both of Fiiunark and l']nghuid. 

 Like Ariijifopdccus Olfersii, it is a ])elagic and noc- 

 turnal iish tif extensive geograi)lucal distribution. It 

 I has been found on both sides of the North Atlantic, 

 I and differs but slightly, if indeed it be specifically 

 distinct, from Mautolicus a))iethi/sfuio-piindafiis, a Me- 

 diterranean species with which GCnther has combined 

 MaiirolicKS (iKsfralis, a New Zealand form described 

 by Hecti Hi. 



\\'ithiii the limits of the .Scandinavian fauna the 

 Pearl-side was first discovered by Strum off SondmOr, 

 and on the Swedish coast it was first taken by Nilsson, 

 near Gothenburg, in a seine drawn for small Herrings. 

 It has since been found at many points, both in Bo- 

 husliin and Norway, cast ashore by the waves, or in the 

 stomach of Cod and Herring". South of Bohuslan it is 

 unknown on the Swedish coast, and only one find has 

 been recorded on the west coast of Denmark, consisting 

 of a specimen lying on the shore at Hjorring in the 



north of .lullaiid. On the Norwegian coast it is much 

 commoner, north to llaminerfest, and ascends the fjords, 

 in the La iig, one of the Finmark fjords, east of Tromso, 

 there appeared in 18tj6, according to CoLLETr, a whole 

 shoal of Peai'l-sides. They could be scooped up in 

 bucketfuls from the surface, and at least 50 .specimens 

 were pi-eserved. Similar shoals have been seen on the 

 coasts ol Great I'lritain and Ireland, in the North Sea, 

 the Channel, and tiie Ii-ish Sea. According to Edwakd' 

 the Pearl-side is a regular winter visitor off lianff, 

 never failing to a]j])ear in the; month of January; and 

 from January to Mai'ch Mr. Sim gathered in two years 

 nearly 2(J0 specimens on tlie shoi'e near Aberdeen. It 

 would thus seem to be most conunon to the north; on 

 the English coast south of \'orkshire only solitai'\' spe- 

 cimens have been found, and on the west coa.st of 

 France, as well as in Holland, the species is unknown. 

 On the east coast of N(jrth America it is stated to 

 occur but seldom. 



The small teeth and fine gill-rakers of the Peai'l- 

 side show that it lives on minute animals. Tfie.se con- 

 sist principalh", we may assume, of the small crusta- 

 ceans (Entomostraca) that are so abundant in high 

 northern latitudes", and \vhich compose the chief food 

 of tlie Herring too, though the latter, as we have seen, 

 also preys, like Argyropelecus Olfersii, on the Pearl-side. 



During winter, when the Pearl-side appears in such 

 numbers oft' the Scotch coast. Day examined its gene- 

 rative organs, and found the comparatively large eggs 

 and the milt almost ripe in February. We may hence 

 conclude that the spawning is performed in spring. 



Subfamily S A U R I N JE. 



Body of oiilif slii/lifh/ irrei/iilar Herrivg-forni, or more terete and elongated. Ventral margin more or less terete. 



Cleft of tlie month large and horizontal or only slightly ascending. Internuuillaries extending to the termination 



of the margin of the upper jaw. Teeth in the mouth of fairly uniform size. Preahdominal length less than the 



postahdomincd. Snout shorter than the postorhital part of the head. 



By the more forward situation of the \eiitral fins ceding ones, so far as regards the general rules for the 

 and the greater elongation of the intermaxillaries this ! development of the Teleosteous type in these respects, 

 subfamily is raised to a higher rank than the two pre- But in the first-mentioned character these fishes come 



■" Teybom fciund a Pearl-side about 7 cm. long in tlie stomach of a female Herring measuring 311 mm. tliat was taken in a drift- 

 net off Vinga on the 8th Sept., 1885. 

 ' See Day, 1. c, p. 51. 

 ' CoLLETT also found in the stomach of the Pearl-side Culunus Jinmarchicus. 



Scandinamnn Fishes. 118 



