1883.] PROF. FLOWER (IN TH re DELPHINID.«. 48.5 



very well-marked species are common in every museum \ there is, 

 so far as I am aware, no skeleton or any part of a skeleton which 

 certainly belongs to it preserved anywhere, and very few of the skulls 

 have localities assigned to them. In the Leiden Museum two are 

 said to be from the " Indian Ocean " and one from the " Atlantic ;" 

 Indian Ocean, Red Sea, and the Pacific are the localities given by 

 Dr. Gray ; while Van Breda's specimen, supposed to belong to this 

 species, and from which alone its external characters are known, 

 came from the coast of Holland. It does not appear to have been 

 met with hitherto in the seas around New Zealand or Australia, or 

 in the North Pacific. 



Among the skulls of this form of Dolphin are two well-marked 

 varieties, distinguished by the amount of lateral compression of the 

 rostrum. To the broader form the name of rostrafiis is more pro- 

 [lerly applied : while those (otherwise quite similar) with a very 

 compressed rostrum have been specifically distinguished by Gray 

 under the name of Sterm compressns (Erebus and Terror, p. 43, 

 tab. 27, 1846). Sjiecimens of this form from the Indian archi- 

 ])eligo were, however, previouslj'^ described by Schlegel (Abhandl. 

 p. 27, Taf. iii. figs. 2 & 3, 1841) as DeJphinus reimvardtii, which 

 name will therefore have the priority if it should prove to be a 

 good species. 



In the series of ten skulls in the British Museum the two extreme 

 forms look very distinct, but others are quite intermediate ; and when 

 the whole series is placed together in order such a regular gradation 

 can be traced, that it becomes impossible to say where the broad 

 form ends and the narrow one begins. Dr. Gray evidently met with 

 this difficulty, as the names attached to the skulls show ; some which 

 are marked by him 5'. compressns being indistinguishable from others 

 labelled /S^./row^«^?/5. In the series at Leiden exactly the same 

 occurs, the two forms passing insensibly into each other ; and there is 

 one among them that has a shorter and stouter rostrum than an}' 

 which I have seen elsewhere. The broad form appears to be the most 

 common in collections. Bearing in mind the observations quoted 

 from Fischer upon the sexual characters of the skulls of D. delphis 

 and D. tursio, the question naturally arises whether the different 

 forms observed in the skulls of this group may not have the same rela- 

 tion to one another. Unfortunately there are no materials available 

 at present for its solution. The teeth are sculptured in both, but are 

 generally rather more numerous in the narrow than in the broad 

 skulls, being usually 23 or 24 in the former and 20 to 23 in the 

 latter on each side of each jaw. The extreme length of these skulls 

 varies between 520 and 550 mm. 



A very important contribution to the history of this group of 

 Dolphins has lieen made by the publication of a good description 

 and figures of both external and anatomical characters of a specimen 

 captured in the South Atlantic in September 1874, in 32° 29' South 

 lat. and 2° 1' West longitude, by the officers of the German ship 



1 There are 10 iu the British Museum, the same number cat Leiden, at 

 Paris, and 5 in the Museum of the College of Surgeons. 



