40 Dr. F. A. Bather on Protoechinus, Austin. 



posteriorly 6'2 ; interorbital breadth 9*5 ; breadth across 

 brain-ease 17*8 ; palatilar length 21; upper tooth-series 10; 

 diagonal diameter of/; 4 3*6, of m 1 3*5. 



Hub. " East side of the Andes near Fort San Rafael, 

 Province of Mendoza." 



Type. Adult female. B.M. no. 60. 1. 5. 2. Collected by 

 Mr. T. Bridges. Presented by G. R. Waterhouse. 



Mr. Bridges collected in this region a number of tuco-tucos 

 which have hitherto been assigned to Philippi's Ctenomys 

 mcndocinus*, but I now find that they belong to two quite 

 distinct species — the one with normally inflated rounded 

 bullw and the other with very narrow ones. Now it fortu- 

 nately happens that the Museum contains a series of 

 mammals purchased of Gerrard in 1873 which were labelled 

 with Philippi's names in what I believe to be his handwriting, 

 and among them is a tuco-tuco from " Mendoza " labelled 

 Ct. mendocinns, which, in the absence of other evidence, we 

 may accept as typical. This specimen has the full rounded 

 bullae usual in the genus, and I therefore describe as new 

 the one with the narrow bulla3. 



VI. — Protoechinus Austin. 

 By F. A. Bather, D.Sc, F.R.S. 



(Published by permission of the Trustees of the British Museum.) 



[Plate II.] 



Previous History. 



In December 1860 Fort-Major Thomas Austin published in 

 ' The Geologist ' (iii. pp. 446-448) a paper " On a new 

 Genus of Echinoderm, &c." This was Protoechinus, so called 

 because its author believed it to be " one of the first, if not 

 the very first true echinus, that appeared on our globe." 



The Genotype was the unique species Protoechinus anceps, 

 of which three specimens had been "found in the lower beds, 

 but not the very lowest, of the Carboniferous Limestone 

 [Lowest Tournaisian], at Hook Point, county of Wexford/' 

 Ireland. One of these specimens "fell into unscientific 

 hands, and was lost to science." Another was imperfectly 

 preserved. Of the third a rough woodcut was given, and it 

 is this which must be regarded as the Holotype. 



The Holotype is No. 401 of the Austin Collection in the 

 * Arch. f. Nat. xxxv. p. 38 (1869). 



