1895- MORPHOLOGY AT THE NATIONAL MUSEUM. 263 



labels are affixed to the several parts of the drawing. When fossil 

 specimens are either not obtainable on account of their rarity, or are 

 too large for exhibition in the series, their place is taken by labelled 

 drawings ; and when the outline or position of any structure is not 

 sufficiently obvious, e.g., the sutures of bones, the teeth of small 

 skulls, and the organs of the lateral line, recourse is had to the 

 judicious application of a little bright colour. 



It will be noticed that the classification adopted is alternately 

 systematic and anatomical. Thus, the Vertebrata are first divided 

 into the classes, Birds, Reptiles, Amphibians, etc., and the pre- 

 parations illustrating Amphibian morphology are arranged according 

 to the different systems of organs. Integument, Skull, Respiratory 

 System, etc. The specimens in each of these divisions are grouped 

 under the ordinal heads Anura, Urodela, etc., and in many cases 

 structural peculiarities serve once more for the arrangement of the 

 preparations in each order. 



Integument. — The first column is devoted to an exposition of 

 the characters of the integument : the glandular nature of the skin is 

 alluded to, and the periodic shedding of the outer layers of the 

 epidermis is illustrated by the slough of a newt mounted in spirit. 

 ' An epidermal exoskeleton is absent except in the Japanese 

 Salamander {Onychodactylns) and in the Cape Toad [Xenopns), which 

 are provided with claws.' Examples are therefore furnished of the 

 feet of these two amphibians. ' The dermal exoskeleton is also but 

 little developed in living Amphibia. In Cevatophvys among the Anura 

 there is a bony plate behind the skull and in some of the Caecihans 

 there are small cycloid scales imbedded in the skin.' A complete 

 skeleton of Cevatophvys shows the form and position of this dermal 

 ossification ; and a portion of the skin of Ichthyophis, a few isolated 

 scales mounted on black paper, and an enlarged drawing of one of 

 these scales illustrate the second form of dermal exoskeleton. ' In 

 the Labyrinthodontia bony scutes are frequently present on the 

 ventral aspect of the body,' a statement which is illustrated by a 

 drawing of the ventral scutes of Cvicotus. 



Vertebral Column. — ' The vertebral column of Anura is 

 usually composed of nine vertebrae and an unsegmented urostyle.' 

 The series commences with two vertebral columns of Rana guppyi, one 

 showing the ventral surface and with the vertebrae articulated, the 

 other disarticulated and with the articular surfaces of the centra 

 coloured brown and those of the zygapophyses green. ' The 

 vertebrae of Anura are mostly proccclous and devoid of free ribs, but 

 in the Discoglossidcs and the Aglossa they are opisthocoelous, and in the 

 former family the anterior vertebrae are provided with distinct ribs.' 

 Examples : Discoglossus and Xenopus. Then follow a series of five 

 vertebral columns of Anura showing the various degrees of expansion 

 of the sacral diapophyses. The short vertebral columns of the Anura 

 are mounted whole, but in the other orders selected vertebrae only are 



