2 WHEELER. [Vol. XV. 



The specimens vary considerably in length. The youngest 

 individuals, evidently just born, measure from 13 to 20 mm., 

 the adults from 40 to 57 mm. One female only 30 mm. in 

 length contains full-grown pigmented embryos. 



Dr. Eisen informs me that the preservation in alcohol has 

 not altered the colors of the animal. These are very variable, 

 the dorsal surface of the body and legs ranging through some 

 four or five shades, — from light pinkish brown in many of the 

 youngest specimens to a dark reddish chocolate color in some 

 of the oldest. Most of them show a distinct darker brown 

 median dorsal stripe, and some have the faint transverse inter- 

 segmental stripes indicated in the figure (Fig. i). Along 

 either side of the mid-dorsal line are seen a number of white 

 dots, which are in reality the unusually large pale papillae seen 

 under a higher magnification in Fig. 8. The ventral surface, 

 too, is variable in its coloration. Some specimens are pale 

 yellow, like Figs. 2 and 5, others are white, still others flushed 

 with pink. The lips of the oral orifice, the oral papillae, and 

 the spinous creeping pads on the feet are paler than other por- 

 tions of the ventral surface. 



The transverse ridges of the integument bear each a single 

 row of papillae. Some of these are enlarged, especially on 

 the legs, and consist of two segments, — a broad basal moiety 

 which is usually conical, although in some cases it approaches 

 the condition called "cylindrical " by Sedgwick ^ in his descrip- 

 tion of P. edwardsii, and a more slender tapering apical 

 moiety, tipped with a spinule and unpigmented. It would 

 seem that the animals have the power of retracting the pale 

 distal moiety with its spinule, but this can only be determined 

 by a study of the living animal. 



In the mid-dorsal line the transverse ridges of the integu- 

 ment are interrupted by a delicate but perfectly distinct im- 

 pressed white line (Fig. 8). The absence of this white line 

 is emphasized by Sedgwick as a diagnostic character of the 

 American, or neo-tropical, species of Peripatus. I find this 



1 Adam SedgT^ick, " A Monograph of the Species and Distribution of the 

 Genus Peripatus." Quar./oiirn. Micr.Sci., vol.xxviii, 1888. Also in Studies from 

 the Morph. Lab. Univ. Camb., vol. iv, pt. ii, 1888, pp. 147-212, Pis. XIV-XX. 



