— 107 — .lOH.S. SCIliMIDÏ 



IV. SCHEME FOR THE DETERMINATION OF THE 



POSTLARVAL STAGES OF THE NORTH ATLANTIC 



GADOIDS DEALT WITH IN THIS WORK 



Keferring for all details to my earlier descriptive papers (see note p. 8), I may give 

 here a brief summary of .the priiieipal characters, by means of which the postlarval stages 

 of the gadoids dealt with here can be distinguished. First of all, a synopsis of the genera 

 is given (A), then a synopsis of the species of the genus Gadus (B) and lastly a synopsis 

 of the species of the genus Molva (C). The remaining genera, namely, Merluccius^ Rani- 

 cep!f and Brosmius are represented each by only one species. 



A. Synopsis of the genera 



I. Ventrals not prolonged Gadus (incl. Gadiculus) 



II. Ventrals prolonged 



(1) Postanal pigment typically arranged in 3 bars (I, II, III) the most post- 

 erior (I) lying near the end of the tail*. 



(a) Ventrals much prolonged, reaching far past the anus, 



a. Ventral rays free nearly throughout their entire length, swollen 



at their tips Brosmius 



ß. Ventrals rays united by a membrane, thin at their tips Molva 



(b) Ventrals not very much prolonged, not reaching far beyond the 



anus Merluccius 



(2) Postanal pigment not arranged in 3 bars (I, II, III) the most posterior 



(1) lying near the end of tail • Eaniceps 



B. The Species of Gadus 



A. The youngest postlarval developmental stages up to about 8—10 mm. in length 



I. Main group. 3 (or 2) postanal transverse bars of pigment (3, 2, 1) are 

 present arranged according to the type represented on page 46. (In G. 

 poUachms the bar arrangement has disappeared owing to the fusion of bars 2 and 3). 

 (a) Bar 1 is present 



Only the ventral portion of bar 1 present. Dorsal pigment less pronounced 



than the ventral. Abdominal vertebrae 18 — -19 Gadus eallarias 



Only the dorsal portion or both dorsal and ventral portions of bar 1 present. 



Dorsal pigment more pronounced than the ventral Gadus saïda 



* In Molva molva the most posterior of the 3 postanal bars is wanting, but the two others are 

 present and have the typical position. 



