SYNEXTOGNATES. 



34S 



psfiidoi'ins oil tlic liiiul iii.-iraiii, like llic still more pru- 

 iiiiiiciit Lirowlhs ill llic (i.-moid ii'ciius I'ohijitcniS. 



Ill tlic Syneiitogiiiitcs tlic system ol' the latcrnl line 

 is inosf hiii'liK' (Icxcldjicd in the hitcrnl line ilsclf, wliicli 

 is sitii.'itcd Idw diiwn, .•nid ucncr.'dlv runs nlong" ii. soiuc- 

 w lint ('lc\;i.ted cai'iii;i on each side ol the belly t'roiu the 



surface of tlie shell (tig. 91). By means of these fila- 

 ments the eggs ai'e united into c;lusters or attached to 

 seaweed or otlier objects at tlie liottoni of the sea, the 

 water in which \\u'\ lie, being thus constantly changed 

 b\- tiie ebb and f^o^v of the tide. 



The Synentognates ai-e active surface fishes, the 



)\\<'r anterioi- corner of the cla\ iciilar region to the liase ' great majovity of them being i)ela,gic; but some of them 



of the caiulal till, being more or less complete thvough- 

 out its course. Sometimes, on the tail behind the anal 

 tin, it cur\('s iipwards on a middle carina along each side 

 of the liod\ , and ad\ances o\ er the membrane between 

 the middle viiA's of the caudal tin. However, the lateral 

 line, as usual, originates in the temporal region, and a 

 coiinecti\(' branch, which is often \isible e\ternalh% runs 

 downward liehind the pectoral fin and joins the ventral 

 branch below this point". The system of the lateral line 

 on the head generallv opens into a number of scattered, 

 small, round pores on the |)ostteinporal lione, the tem- 

 poral region, anteriorh- on the forehead above the eves, 

 .sometimes out on the interniaxillarA- l)ones, wlieii thev 

 are elongated, and also on the posterior and inferior 

 margins of the prcopcrculum, from which jioint the row 

 is continued on the branches of the lower jaw, when 

 th(>\- are elongated. 



The ova of all these fishes, to the liest of our know- 

 ledge, ai-e furnished with filaments on the shell\ like 

 those we ha\e noticed abo\e in (ii)bhfi iiiger, but ar- 

 ranged in a different manner, being scattered over the 



enter the lagoons, or, like several of the Mugiloids, 



Fig. 91. Egg of a Garpilce enclosed in the shell, which is furnished 

 with lentaciilai' threads on the surface. The egg had undergone fer- 

 tilization 3 h. "23 min. previously. Germinal disk (17) divided into 

 8 segments. Magn. H'/g diani. After Ryder. 



ascend the rivers, or are even statioiiar\' fresh-water or 

 brackish-water fishes. According to GCnther's Catalogue 

 about 180 species have been named, defined with more 

 or less certaintv and distributed among 5 genera. Gill 

 and Bi.EEKEii have subsequenth' adopted 13 di.stinct 

 genera for these forms. ^lost writers have included all 

 the Synentognates in one single farailv, 



k AM. S C M K R E S C 1 D M, 



the characters of \\hich thus coincide with those already given for the whole group. 



On account of the diffei-ence in the jaw-teeth, hoAv- 

 ever, GiLL^ established two families: Beloiiida, with 

 sharp, s])arse teeth, and Sroiiibreso(id(P, with small jaw- 

 teeth or destitute thereof. Bleeker (Afl. Ichth.) adopted 

 four subfamilies: Scomhrp.soc'i formes, with both jaws 

 elongated and with finlets behind the dor.sal and anal 

 fins; Masfacx'Dibeli formes, also with both jaws elongated, 

 but without finlets; Ilemiramphiformes, with only the 

 lower jaw elongated like a spear-head, the ujijier jaw 

 forming a triangle in front of the snout proper; and 



" We have not succeeded in finding a trace of the upper lateral line, which according to V.\lenciennes (Cuv., Val., Hist. Kat. Foiss., 

 vol. XVIII, p. 406) and Bonaparte (Fii. Ital, torn. Ill, 2 — Pcsci — Belone acus) runs along the upper part of the sides of the body. 

 Yai.encie.nnes states, however, that ho has been able to trace the lateral nerve throughout the »-hole of its course. 



' HvECKEL, MOli.er's Arch. f. Anat. 185.'), y. 23, tail. IV and V; KOi.i.ikkr. Verb. Pliys., Med. Ges. Wiirzh., vol. VIII (1858), p. 80; 

 UYnEi!, Bull. U. S. Fish. Coram., vol. I, p. 283, pi. XIX— XXl. 



' An-. Fam. Fish., Smiths. Misc. Coll., Xo. 247. ]>. 14. 



lastly, Exocoetiformes, with neither of the jaws elong- 

 ated into a l)eak. The first three subfamilies are fur- 

 ther distinguished from the fourtli l)y the fact that in 

 their case the maxillary l)ones are more or less firmly 

 united to the lateral parts of the hind superior margin 

 of the intermaxillary bones, in a manner which calls 

 to mind the .structure of the Plectognates, though here 

 these bones may more easily be distinguished from each 

 other, while the intermaxillary bones have a thin, but 

 liroad mar<fin straight across the snout, and articulate 



