500 PROF. FLOWER ON THE DELPHINTDiE. [NoV. 20 



In all the premaxillee are very thick and prominent, and bordered 

 by a strong groove laterally. They vary considerably in comparative 

 width and length of rostrum, stenorhyncha being the narrowest, and 

 alope the broadest. One of the specimens marked with the latter 

 name has the rostrum considerably wider than the other, approaching 

 very near in proportions to Clymenia euphrosyne (Section B). The 

 College of Surgeons Museum has two specimens belonging to this 

 group, one of which is intermediate between Gray's stenorhyncha 

 and microps. 



D. roseiventris (Hombron & Jacquinot, Voy. au Pole Sud, Zool. 

 t. 1. p. 39), of which there is a skull in the Paris Museum, figured 

 by Gervais (' Osteographie,' pi. xxxviii. figs. 6& 6«), is also of the 

 same form, and, except in its smaller size, closely resembles the ori- 

 ginal longirostris of Gray. It is certainly the same as microps. 



No skeleton of any animal of this group exists in any museum I 

 have visited. 



Delphinus, Linn. 



JEiidelphinus, Gervais, ' Osteographie des Cetaces,' p. 600 



(1880). 



If the name of Delphinus is to be retained as a generic appellation, 

 it is to this section that it properly belongs, as its type is the common 

 Dolphin of the Mediterranean, the "Delphis" of the Greeks; and 

 therefore Eudel^ihinus is a superfluous term. 



The skulls are distinguished from those of all other Dolphins bj* 

 the deep longitudinal grooves which run along both sides of the 

 palatal surfaces of the maxillary bones, separating the alveolar 

 border from a strongly pronounced median ridge. The inner 

 borders of the pterygoid bones meet for their whole length (see fig. 9). 

 The rostrum is long and narrow, greatly exceeding the length of the 

 cranial portion (generally about double), and its width at the base 

 is usually about one third of its length. The teeth are small 

 (not exceeding 3 miliim. in diameter) and numerous, from j^ to 



60 . , . 



Delphinus delphis, of the North Atlantic and Mediterranean, may 

 be taken as the type of this group. In the ' Transactions ' of this 

 Society, vol. xi. plate 1, I gave a coloured figure of the external cha- 

 racters of a young female (5 feet 1 1 inch long) taken off the coast of 

 Cornwall in March 1879. This year (Sept. 17, 1883) I received 

 from Mr. Matthias Dunn another specimen, still younger (only 4 feet 

 4 inches in length), from the same locality. It diifered from the 

 former in having a shorter beak, relatively to its general size, show- 

 ing, as might be expected, that this is a character influenced by age. 

 Though the general distribution of the colours on the surface of the 

 body was the same, there was this one marked difference. The upper 

 white line, which courses along the side above the pectoral fin towards 

 the head, instead of dipping below the eye and running towards the 

 angle of the mouth as in the former one (and also in Reinhardt's ex- 



