386 Zoological Socicfi/. 



companied by a description by StafF-Surgeon Burton, which was 

 read. 



MoNACANTiius Hystrix. Mou. latevibus in medio G — l-spinosis, 

 spinis validis longioribus. 



Guaperva Hystrix, List., in Will. Hist. Pise, App. p. 21. Tab.S. 2 1 . 



" Length 7 inches. Colour black. Skin crowded with rough grains ; 

 a smooth spot behind the gills ; towards the tail assuming the charac- 

 ter of rhomboid scales, but the granular form continued over the caudal 

 fin. On the sides, about one third of its length from the tail, is fixed 

 a cluster of six or seven strong free spines from 4^ to 1 inch in length, 

 capable of erection and depression. 



" Dorsal spine very strong, about 1-^ inch long, sub triangular, 

 with serrated edges, and grained, except towards the point : when 

 not erected it is lodged in a deep groove on the back. Extremity 

 of the pelvis salient, and terminating in two sharp short spines. Se- 

 cond dorsal fin broad and 2 inches long ; anal similar, but shorter. 



" In front of the eyes a small /ossa covered with a membrane, ex- 

 cept in its centre, where it is perforated by a minute olfactory fo- 

 ramen. 



" Teeth in the upper jaw eight, the two middle incisors placed di- 

 rectly in front of the second pair, in a groove of which they are 

 lodged, so that no part of these last are visible externally, except a 

 small process at the cutting edge ; the outer teeth trigonal. The 

 teeth of the lower jaw differ materially from the generic character, 

 their number being only four, of which the two middle ones are 

 by far the largest in the mouth. On this account, and also on ac- 

 count of the nature of its covering, — which partakes of the granular 

 character of that oi Monacanthus smdAluterus, Cuv., and of the rhom- 

 boidal scales of Balistes,^]., — this fish might be regarded as the type 

 of a distinct subgenus among the Balistidce. 



" The strong dorsal spine, the spinous processes of the pelvic 

 bones, and the cluster of lateral spines, added to the tough indu- 

 j-ated epidermis of this fish, form an armour excellently adapted for 

 its protection against its more powerful enemies. 



" It is an inhabitant of the Indian Ocean, frequenting the shores 

 and coral reefs. The present specimen was brought from the Mau- 

 ritius by Dr. Hibbert, Surgeon, 99th Regiment. This species is 

 stated to be also found abundantly on the western coast of Australia, 

 where it is known to the settlers by the name of " leather-jacket," 

 — a denomination which is probably applied to it in common with 

 other species of Balistidce." 



Mr. Gray exhibited a drawing of this specimen, and stated his 

 intention of publishing a figure of it in the concluding Number of the 

 ' Illustrations of Indian Zoology,' which is about to appear. 



Mr. Gray called the attention of the Meetmg to two new species 

 of Sturgeon ; one from China, of which he exhibited a specimen, and 

 the other from the Mississippi, of which he showed a drawing taken 

 from a specimen in the British Museum. The former species belongs 

 to the same section of the genus with the Acipenser glaher of Mar- 

 gigli, characterized by its conical muzzle, and the smooth and silvery 



