()0() 



SCANDINAVIAN FISIIKS. 



Hot ()nl\' with its OAvn vertelira, but also with the 

 fourth. The rilis of tiic latter have assumed the form 

 of disks united to its back. In Ficrasfrr (h'iitiifi(s the 

 thii'd pair is onh' s]i;:ht]\' extended, the second and 

 tirst pairs all the more .so, though far less than the 

 third pair in the former species. To these bones is 

 attached the anterior part of the air-liladdei' — which 

 extends along the wiiole dorsal wall of the abdominal 

 cavity, which is nuieh liroader in acus than in deiifntiis 

 — and here are extended muscles to draw tlie air- 

 bladder forward, among which the median are especially 

 large and powei'ful, originating from and coasting the 

 )jarasphei|oi<i Itone and attached to the anterior end of 

 the air-bladder. 



The eggs of these tishes are developed floating 

 in the sea, united \\ithin a slimy mass, like those of 

 the Angler. (If the spawning (deposition of the eggs) 

 we know only that it takes place at night. The deve- 

 lopment advances (|uicklv. i3v the sixth dav the volk 

 is absorbed, and the larva begins to eat. It is now 

 (m\y ?> or 4 mm. long, but already Eel-sha])ed, and, 

 in F'lerasfcr acus, has a singular appendage on the 

 hack, almost as long as itself. This is the first ray 

 of the future dorsal fin, •\\diich has early gro^vn into a 

 long, stiff stem, \vith foliate growths set alternately. 

 Here we auain meet with an examiile of the long 



appendages ^\•hich we have alreadv observed on several 

 occasions in the larva- of pelagic fishes, and which help 

 the larva' to supjiort themselves as they float in the 

 water and di'ift with the current. These appendages 

 probably give the larva' a protective likeness to small 

 Medusa", and perhaps, as Emeuy supposes, serve as a 

 lure to entice the small crustaceans (Entomostraca) on 

 whieli the larva? live". This evanescent growth does 

 not ap]iear in the larva oi Fierasfer dentotus, \i\ which, 

 on the other hand, the body is still more elongated 

 and resembles a long, narrow riblion''. In the case of 

 this larva, Emekv has also made the observation that it 

 possesses a considerably greater luuuber of vertebra? 

 than the full-grown fish, \vhich generally has only 95 

 vertebra^ (26 abdominal), while in one larva he found 

 175 vertebra'. In adult sjjecimens ni' Fierasifcr dcjifafus 

 too, the tip of the tail is often bi'i;)ken off short, and 

 bears a secondary growth, corresponding to a caudal 

 fin, such as we have above seen to be common among 

 the Macruroids. E.mekv was therefore quite justified 

 in his suspicion' that Fierasfer dnitafas in later years 

 discards its shelter within the sea-cucumber, or at all 

 events cannot gain entrance in the same manner as its 

 congener, although he subsequently'' met with a small, 

 but full-grown specimen (with 115 vertebra') in a 

 IloJofJiiuitt tidiulofia. 



Gems fierasfer. 



Pcitoral Jiiif! jiresenf. Braiichioster/al rai/s 7 . Pseudohranch'KC irctiifiiif/. BiaiirhidstefiuJ mcttiJiraiivs Knifed laider- 



iKjdili, hid free from flie isfhiinis. The upper jmv projects slightly heijond the lower. Cardiform' teeth in the 



j'a/rs, (11/ the vomer, and on the puJatine hones. Anal aperture nearly rerticalhj below the insertions <f the 



pectoral fns. Pijloric a/ijiendacjes radinientari/. 



This genus seems to attain the highest point of its 

 development in Indo-Australia.n waters, where 5 or (! 

 species are kn(j\vn. One species has l)een described 

 from the east coast of Africa, one fi'om Central Ame- 

 rica, and two from Europe. In 1853, during the voyage 



round the world of the frigate Eugenie, Professor H. 

 KiNBER(i took near the Keeling Islands specimens of 

 Fierasfer parri/iiiinis 31 cm. in length and with a 

 depth of 23 mm. just behind the head. Tlie other 

 species of the genus are considerably smaller. 



" lu Kalt (Ann. Mag. Nnt. Hist., ser. ?., vol. VI (IHGO), p. 27'2, tab. Ill, tig'. /)) tliis larva has borne the name of Porobmnchiis 

 linearis, in Gascu and subsequently in CosTA (.^niiario tlel Museo Znologico ili Napnb', Anno V, tav. I, tig. 1) tliat of \'e.TiUifi'r <le Filippi. 



'' .Another characteristic, as yet observed only in the larva of Fients/cr nctis, is that tlie tip of the tail ends, as in the Macrnroid 

 larviv {Krohnius), in a long, filamentous prolongation. 



' Fn., Fl. Golf. Neap. II, Monogr. Fieras/., p. 18. 



<* Mitth. Zool. Stat. Neap. Ill, p. 282. 



" Thougli sometimes small. 



■' Sometimes set in one row in the jaws. 



