ON THE MOLAR SERIES OF RHINOCEROS TTCIIORHINIJS. 552 
number very exactly. Now, Cuvier and Valenciennes, it is true, 
may have registered 4200 species as described in their joint work, as 
being in the French collection. But it is now well known, that many 
of Cuvier and Valenciennes’ species are fictitious, the same fish 
having been in many instances described under half a dozen or more 
different names. We believe, therefore, that there is no reason to 
doubt of the superiority of the British to the French collection in 
this class of animals ; though, if Professor Agassiz’s estimate of 
species at Cambridge be correct, both of them must yield the palm 
to their transatlantic rival. 
Professor Agassiz is likewise satisfied, from the rapid examination 
he has himself made, of the Echinoderms and Corals in the British 
Museum and Jardin des Plantes, that the Cambridge collections of 
these classes are “ inferior to none, even if they are any where 
equalled.” 
Original 
LVI. — On the Molar Series of Bhinoceros Tichorhinus. 
By W. Boyd Dawkins, B.A. Oxon., F.Gr.S. 
Contents: 
§ 1. Introduction. 
§ 2. System oe Measurements. 
§ 3. Common Characteristics of Per¬ 
manent and Deciduous Molar 
Dentition. 
4. Dental Formula. 
5. Characteristics of Permanent 
Upper Molar Series : — 1.— 
Pm 2. 2—Pm 3. 3—Pm 4. 
4— Ml. 5— M2. 6— M3. 
§ 6. Characteristics of Permanent 
Lower Molxrs: — 1—Pm 2. 
2— Pm 3. 3 —Pm 4. 4—M 1. 
5—M2. 6—M3. 
§ 7. Characteristics of Upper Milk 
Molars:— 1—Dm 1. 2—Dm 2. 
3— Dm 3. 4—Dm 4. 
§ 8. Characteristics of Lower Milk 
Molars: — 1 — Dm 1 . 2—Dm 2. 
8—Dm 3 and 4. 
Figures of the Upper and Lower Milk Series , and of Pm 2. 
§ 1. Introduction.— My object in the present communication is to 
reduce to some sort of order the classification of the Molar Series of Rhi¬ 
noceros tichorhinus , and to define, as far as possible, each tooth from its 
homologues in other species. This I am able to do with considerable 
accuracy, by the application of a system of terms and measurements, 
that I have found invaluable, not only in the present instance but also in 
determining the more difficult Artiodactylian teeth, and by the charac¬ 
teristics which obtain in the large numbers that have passed through 
my hands. The generalizations are based upon a careful examination of 
seven jaws and upwards of 200 teeth, from Wookey Hole, of those in 
