294 NOVITATES ZOOLOGICAE XXIII. 1916. 



shores of the Baltic and North Sea. This form I would call Phalacrocorax carbo 

 carlo (L.). 



(2) Die Eisscharbe. Carbo glacialis, Brehrn. 



Described as being smaller (the measurements showing a slight difference and 

 the bill overlapping) and also having a blue-black gloss, as in No. 1. Habitat : 

 Greenland to Faroe, in winter to Iceland, and from Faroe to the German shores of 

 the North Sea. This is clearly a synonym of P. carbo carbo (L.) 



(3) Die Baumscharbe. Carbo arbor eus, Brehrn. 



Described as having the size of C. glacialis and the long tail of C. cormoranus, 

 but with a more highly-arched skull and shorter bill, also a differently-marked 

 juvenile plumage. Of its distribution Brehrn says that it had immigrated into 

 Denmark about thirty years ago (which would mean about 1800), but that it was 

 everywhere persecuted and driven away, laid its eggs in empty nests in heronries, 

 came to the German shores of the Baltic and North Sea, and slept on trees. He 

 adds that it formerly lived by thousands in several places, whence it had been 

 driven away. The question is, whether this name can be adopted. In my opinion 

 it is uncertain ; evidently Brehrn had only young specimens, and there is nothing 

 in the description to show that the bird described belonged to the smaller ftrnn ; on 

 the contrary, he distinctly says that it is as large as his C. glacialis, with the tail 

 even longer ! The Brehrn collection contains no specimen from Denmark and only 

 a young bird from Rügen marked as arboreus. It is not clear that the bird 

 described was from Denmark and one of those formerly nesting there, and that 

 the information as to its appearance and disappearance referred to birds of the 

 smaller race. We must certainly assume that this was the case, because a 

 specimen from Tunen, killed June 1, 1856, and others from Halstein in the 

 Copenhagen Museum, belong to the small race ; but we do not know whether 

 Brehrn described this race, as his description points rather to the contrary. On the 

 other hand, under No. 4 Brehrn describes beautifully the Central European race. 



(4) Die kleine Kormoranscharbe. Carbo subcormoranus, Brehrn. 



Described as being very much smaller than C. cormoranus, differing from it 

 as C. corone does from C. corax in size (Brehrn liked striking comparisons), and 

 having a bluish-green instead of blue-black gloss ! 



It lives and nests in Holland. The collection contains a very fine adult male 

 shot near Rotterdam, May 8, 1823, which agrees perfectly with Central European 

 ones, and is evidently the specimen described. Thus the description of subcormo- 

 ranus is excellent and absolutely certain — a type with exact locality, an adult 

 male, is extant ; it is therefore more desirable to adopt this name than the some- 

 what uncertain name arboreus. The fact of the nesting on trees is not a sure 

 criterion of the subspecies. While P. carbo carbo now apparently nests on rocks 

 only, there was once upon a time a colony in Norfolk on trees, though it must be 

 admitted that I have not seen a specimen from that colony to say that they were 

 P. c. carbo and not subcormoranus. 



On the other hand, P. carbo subcormoranus nests on trees- — sometimes in 

 heronries — but on some seashores, as for example in the Mediterranean, on cliffs, 

 and exceptionally even among reeds. 



We. must thus clearly separate two European forms of Cormorants as follows : 



