18C7-] MR. ST. GEORGE MIVART ON INDRIS DIADEMA. 247 



them. They use their ' flukes,' or caudal fins, niucli less than the 

 Right or Whalebone Whales. They will often lock their jaws, and 

 turn on their sides and twist about. As to this being the cause of 

 deformity, of course it is only opinion, but the general opinion. Such 

 deformed Whales are generally fat ; but this is accounted for by the 

 fact that they are generally 'lone,' or single Whales, and their food, 

 which is the Squid or Cuttlefish, can be nearly as easily captured by 

 the deformed jaw as by the other. The Sperm-Whale will often in 

 his ' flurry,' or death struggle, vomit up large pieces of Squid. Our 

 place being eminently a whaling city, portions of the skeleton of the 

 Sperm-Whale, such as jaws, skulls, &c., are often brought home in 

 our whale-ships. Should any of these be of use to you, I will endea- 

 vour to send you such as you may require, or any other specimens of 

 natural history which may be of service to your honourable Society. 

 " I notice also a paper in the * Proceedings ' (1864, p. 1/0) on the 

 Bonnet of the Eight or Whalebone Whale. Such appendage or 

 bonnet is an invariable portion of the Right Whale from the North- 

 west Coast and Arctic Sea ; it is a development of the cuticle, similar 

 to the nails of Mammalia, or the hoofs of the Ruminants." 



The following papers were read : — 



1. On the Skull of Indris diadema. 

 By St. George Mivart, F.Z.S. &r. 



(Plate XVIII.) 

 Indris diadema. 



Propithecus diadema, Bennett, Proc. Zool. Soc. 1832, p. 20. 



Macromerus typicus, A. Smith, South African Journal, 2nd. ser. 

 ii. p. 49 (1833). 



Lemur diadema, De Blainville, Osteographie, Primates, Lemur, 

 pp. 23 & 37, pi. 8 (skull), pi. 1 1 (immature dentition). 



Habrocebus diadema, Wagner, Schreber, Suppl. i. (1840), p. 2G0 ; 

 V. p. 141. 



Propithecus diadema, Lesson, Species des Mammifcres (1840), 

 p. 219 ; Van der Hoeven, Tijdschr. v. Nat. Gesch. xi. p. 44 (1844) ; 

 Isid. Geoif. St.-Hilaire, Catalogue des Primates, p. (J8 (18.t1) ; Uahl- 

 bom, Studia Zool. p. 203 ; J. E. Gray, Proc. Zool. Soc. 1803, p. 133 ; 

 St. George Mivart, Proc. Zool. Soc. 18G4, p. 638, and 1866, p. 167. 



In March 1866 I had the honour of laying before the Society a 

 description of a skin, a skull, and some other parts of the skeleton 

 of the Woolly Lemur (Z. lanif/er of Linnaeus). At the end of that 

 paper I gave the distinctive characters of that form and those of the 

 Indri, adding such ones of P. diadema of Bennett as I had been 

 able to gather from the scanty materials then accessible. 



I am now enabled to complete that memoir, through the remark- 

 able kindness and liberality of Professor Peters of Berlin, who has 

 not only transmitted to me for examination a perfect and nearly 

 adult skull of the Projrithecus diadema of Bennett, but has expressly 



