JoHS. Schmidt: Gadiculus argenieus and Gadietdus Thori. 5 



On the basis of the material collected by the 'Thor" Expeditions in the North At- 

 lantic I had described, in the papers just cited, the pelagic, postlarval stages of all the 

 11 species of Gadiis occurring in the region and showed, among other things, that they 

 could be readily distinguished especially by means of the distribution of the primary 

 pigment. I was surprised, therefore, on my first expedition to the Mediterranean in 

 1908 — 1909, to find in many haiils in the western basin and round Gibraltar the post- 

 larval stages of a Gadus species (3 dorsals, 2 anals), which difTered greatly from all the 

 known species. Of these it seemed only possible to refer them to the Mediterranean 

 form of Gadus mintUus ("capeian"), which Lilljeborg (1891) considered different from 

 the northem form, and which was the only species, whose postlarval stages I had not 

 seen. Yet the pigmentation was so totally different from that of the northern Gadus 

 minutus, that I could scarcely believe, that the specimens belonged to a form nearly 

 related to Gadus minutus. Further, the next station yielded specimens which were so 

 far advanced in development, that it could be said with certainty, from the position of 

 the fins and number of rays etc, that they did not belong to "le capeian". And on the 

 second expedition to the Mediterranean in 1910 the pelagic stages of the same Gadoid 

 were also found in such considerable quantities, that I was able to conclude, that the 

 species must be common in the Mediterranean. What distinguished the species at the 

 first glance was the presence of posterolateral, trans verse pigment bars, which resembled 

 not a little those I had found in Merluccius (1907). From this and from the absence 

 of a mediolateral streak it could be concluded, that the specimens belonged neither to 

 the first nor to the second of the 3 principal groups, into which I had subdivided the 

 Gadus species according to the primary pigment (1906, pp. 17 — 19). On the other band, 

 they could be placed in the group (containing Gadiculus), which is characterizcd by: 

 "Mediolateral streak wanting. A posterolateral transverse bar present", with the modi- 

 fication, that not one only but 3 transverse bars occurred here. 



Reasoning in this way I came to the conclusion, that this must be a Gadiculus species 

 and that the Gadiculus genus must therefore contain several species. Further investiga- 

 tion showed the correctness of these conclusions and a new proof was thus added to that 

 already obtained of the systematic importance of the primary pigment's distribution 

 in the Gadoids. 



.All postlarval stages are present in my material, from a longth of ca. 4 to ra. 30 mm. 

 At this place, however, I shall not cntcr upon a description of the postlarval development 

 with figures, but restrict myseif to a brief account of the differences botween our spoci««« 

 and the northern Gadiculus. Figs. 1 and 2 represent the two species, the northem and 

 the southem, at almost the same stage of development. Whilst the first has a length 

 of 10 mm., the second is only 7 mm. long. This shows us already, that our specie« is 

 a smaller form than the northern. We see, further, that it is stouter and shortcr in form 



