2 78 THE AMERICAN NATURALIST. [VOL XXXII. 
nerves; this covering becomes transformed into a thick, pigmented, 
lens-like structure. The “eye” proper consists of vacuolated cells 
of a prismatic shape; each is swollen at the free end and tapers at 
the other extremity, at which it is continuous with a nerve fiber. 
It is remarkable that in S. vivíģara no true sensory buds, the cup- 
shaped structures that are found in many Synaptidz attached to’the 
axial surface of the base of the tentacles, were discovered. 
Nerves which supply the cesophagus and mouth region in 5S. 
vivipara are described. Similar nerves in Caudina arenata, ten in 
all, were investigated by the present writer." These nerves have 
been observed in several other holothurians not noted by Dr. Clark, 
and in view of their widespread occurrence it is not improbable that 
they may yet be found in most, if not in all, holothurians. 
In our brief consideration of this interesting holothurian we have 
noted the degeneration of the genital duct, the thinness of the walls 
of the reproductive tubules, and the apertures through the wall of 
the rectum, —all adaptations parallel with a most peculiar manner 
of protecting the young; we have considered the marked degenera- 
tion of the water vascular system, no radial canals being found even 
in the larva, and the significant fact that the tentacles in part spring 
from radial outgrowths of the hydrocoel, as in Cucumaria and Cau- 
dina ; and, finally, allusion has been made to some features of certain 
sense organs which are found not only in Syzapta vivipara, but also 
in other Synaptide. Jonn H. GEROULD. 
= DARTMOUTH COLLEGE, HANOVER, N. H. 
Shufeldt’s Chapters on Natural History.’ 
strikes one in opening this volume is the beauty of many of the 
illustrations, most of them half-tone reproductions of photographs 
direct from nature. Dr. Shufeldt has long advocated this method, 
and the results here presented fully justify his contention. ‘There 
is a life to these illustrations which is lacking from even the best of 
products of pencil and brush; the artist represents the animal as he 
thinks it ought to look ; the camera represents the animal itself. To 
us the best of the illustrations are that of the common swift (Scele- 
porus), those of the green snake and king snake (Cyclophis vernalis 
+ J. B oe The Anatomy P Histology of Caudina arenata (Gould). 
Proc. Bost. Soc. Nat. Hist., vol. xxv Ta 7-74, 8 pl. 1896. Also Bull. Mus. 
Comp. ny vol. xxix, pp. 121-1 ; 
2 Chapters on the Natural History x the United States. By R. W. Shufeldt, 
M.D. Studer Brothers, New York, 1897. 8°, pp. 472 [+ 8]. 
~ 
