390 



SCANDIXAVIAX FISHES. 



undergoes even relative increase. The length of the right 

 branch of the lower jaw shows a remarkable similarity 

 to that of the ventral fin on the same side of the body, 

 and the length of the left branch of the lower jaw to 

 the least depth of the body. 



The lengtli of the abdonunal cavity occupies from 

 V7 to Vg of that of the body; the secondary abdominal 

 cavities extend, as usual, back to the posterior part of 

 the base of the anal fin: we have found the termination 

 of the ovary to lie, on the right side, in a line with tlie 

 18th — 20th rays of the anal fin, counting from behind, 

 and on the left side, in a line Mitli the 26th rav. The short 

 (Esophagus and the stomach extend along the uppei- wall 

 of the abdominal cavity, round the hind margin of the 

 liver, to the middle of the hind wall of the abdominal 

 cavity, where the pylorus is externally divided by a fold 

 from the intestine, at the beginning of which lie three 

 pyloric appendages. A little further along the intestine 

 wo find another, smaller appendage. The first coil of 

 the intestine passes upwards, to the right, and enters the 

 right secondary abdominal cavity for a short distance, 

 scarcely half the length of the albdominal cavity proper. 

 The second coil lies on the iimer side of the first, but 

 does not enter the secondary abdominal cavity. 



The Dab occurs along the whole Avest coast of Scan- 

 dinavia and at least from the Murman coast (Russia) to 

 Iceland. It goes southwards to the Bay of Biscay, and 

 penetrates the Baltic at least as far as Gothland. On 

 tlie American side of the Atlantic it is represented by 

 three very closely allied species", which to a certain 

 extent combine the characters of the Dab with those of 

 the preceding species, as well as of the following ones. 

 A fourth species, which has l)een referred to the genus 

 Limanda'', inhabits the Pacific Ocean, and is distinguislied 

 from the Dab essentially by its larger head and longer 

 pectoral fins alone. A fifth species, Pleuronectes Vegce, 

 wliicli belongs to the same group — with the lower pha- 

 ryngeals like branchial arches, and their teeth pointed 

 and set in t\vo rows — belongs to Japan, and is distin- 



guished by the less marked curve of the lateral line and 

 the extraordinary depth of the base of the caudal fin". 



The Dab (Sw. sandflundra =Sand Flounder), as shown 

 by its Swedish name, generallv keeps to a sandy bottom 

 and at a depth of 10 fathoms or more'', but not un- 

 frequently ascends into shallo\\-er water. Its food is 

 composed of small crustaceans and other marine animals, 

 such as worms, shellfish, starfisli and sea-urchins. SuN- 

 DEVALi, found the stomach and the first coil of the in- 

 testine in one case crammed with small Idoilieidcc (Sie- 

 nosoma), together with pieces of Annelids and sprigs of 

 small aJgte {Ceramium, Fucks). In two females from the 

 vicinity of Cimbrishanin the intestine is distended with 

 a considerable cjuantity of mussels {MytUus eduUs), 

 mostly whole and with the soft parts still undigested. 

 The Dab thus swallows a great portion of its food 

 without crushing it. 



The spawning-season of the Dab occurs in spring 

 and early summer, probably from the latter j)art of 

 April to the month of June. The fry grow slowly. Dav 

 mentions some young specimens, 44 mm. in length, that 

 were taken at the mouth of the Thames, in November, 

 1880. As the young specimens mentioned above, between 

 34 and 133 mm. long, were all taken by Fries in Bo- 

 husliin, on the 19th of May, 1838, Sundevall concludes 

 that they cannot possibh* belong to the fry of that year. 

 "To all appearances," he says^ "the smallest specimens 

 were born in the previous sunnner, of the roe deposited 

 at its beginning. The young specimen 94 mm. in length, 

 which has a far more rol)ust appearance and is of the 

 same colour as the adidt specimens, is evidently a year 

 older, and I would regard it as being of exactly the 

 same age as the lai'ger specimen 133 mm. in length. 

 Both these specimens seem to be in tlieir third year. 

 Hence it seems highly probable that this species re- 

 quires four or five years to attain its ordinary size of 

 from 20 to 2.5 cm." 



In Bohusliln this species is called sandskddda, in 

 Norway sandfynder, and in the Faroe Islands sfl>i(/^Mwrfrfl. 



" Pleuronectei^ (Limanda) fefriigineus ami PL (Limamlu) Beaiiii, botl: with very short pectoral fins, the former also with numerous 

 rays in the dorsal fin (D. 83 — 85) and the latter witli niiconiinonly short liead, its length, according to Brown-Goode, being only abont la 

 "o of that of tlie body. The third species of this group — with the lower pharyngeals narrow, like branchial arches — on the east coast of 

 N. America, Pleuronectes (Psendiiplenrotiectes) americamis has the elliptical shape of the Lemon Dab and the lateral line only slightly curved 

 in front, and shows traces of the more or less tubercular ridge behind the eyes which is characteristic of the group of the Plaice. 



'' Pleuronectes {Liinnnda) asper, with few spines on the scales and with the length of tlie pectoral fin of the eye side about 1 6 "^ 

 of that of the body. 



■•■ D. 69—72; A. .'i4— 55. Least depth of the tail about 9' '., — 1 1 '/o % of the length of the body or 28 — 30 '. of the greatest depth of the body. 



'' LlNDSTiiUM obtained specimens of this species that had been taken at a depth of 70 fthiiis., off Gothland. Buow.v-Goodk's Pleuro- 

 nectes Beanii was taken at a depth of 120 — 12() fthms., off Kliode Island. 



' Tlie same opinion recurs in Kkoyer, 1. c, pp. 314 — 315. 



