_Lagenorhynchus_ has the following assemblage of characters:--Head with short, not very distinct beak. Dorsal and pectoral fins falcate. Teeth small, twenty-two to forty-five in each half jaw. Vertebrae ranging in number from seventy-three to ninety-two. Pterygoid bones either in contact or separate. There are fifteen or sixteen pairs of ribs, of which six are two-headed. Of this genus Mr. True allows eight species, which have been increased by a ninth since the publication of his "Revision."[260] Two species of _Lagenorhynchus_ are known from our coasts; the rest are mainly southern in range. The British species are, firstly, _L. albirostris_, a Dolphin of some 9 feet in length. It has a large number of vertebrae, ninety-two in number. _L. albirostris_ is a rare species, the first record of its occurrence on these shores being in 1834. Since that date some eighteen individuals have been shot or stranded on the shores of the British Isles. The second British species, _L. acutus_, differs in colour from the first. As in the last, the upper parts are black and the under parts white; but in _L. acutus_ there is also a stripe on the flanks, brownish in colour. It has fewer vertebrae, not more than eighty-two. The next genus of Dolphins, _Sotalia_, is characterised by--Teeth tolerably large, twenty-six to thirty-five. The vertebral formula is C 7, D 11 or 12, L 10 to 14, Ca 22. The pterygoids are not in contact in the middle line. It has a distinct beak. Of this genus there are some six species (the exact number, as in so many other genera, cannot be positively asserted), most of which are fluviatile or estuarine in habit. They are also on the whole characterised by their pale, if not actually white, coloration. _S. sinensis_ of the Amoy is white with pinkish fins. _Sotalia guianensis_ is American as its name denotes. It is figured by van Beneden as of a pale brown colour. It is very abundant in the Bay of Rio de Janeiro, and has the reputation of being a friend of man like some other Dolphins. The natives hold that it will bring to shore the bodies of drowned persons. The most singular species of the genus is that recently described by Professor Kuekenthal as _S. teueszii_.[261] This animal is purely fresh-water, being found in {379} the Camaroon river, where it is extremely rare. The nostrils (blow-hole) are prolonged into a snout-like process, a fact which is of interest in connexion with the assertion that in _Balaenoptera_ the blow-hole is puffed out during spouting. What is temporary in the Rorqual appears to be permanent in the _Sotalia_. More remarkable still, perhaps, is the assertion that it is a vegetable-feeding Dolphin. This is not a mere assertion except that it may not apply universally; for in the stomach of a specimen nothing but vegetable debris was found. But in the stomachs of other Whales (e.g. _Rhachianectes_) vegetable matter has also been found, which may perhaps have been taken in accidentally with the food.