182 BULLETIN OF THE 



fawn, darkest on the upper surface of the body, mantle, top of head, and eye- 

 peduncles, gradually shaded off to a dirty white on the edge of the animal, 

 side of foot, back of neck, and lower edge of mantle, and with a similar light 

 line down the centre of back; foot dirty white, without any distinct locomo- 

 tive disk ; edge of foot with numerous perpendicular fuscous lines, alternating 

 broad and narrow ; mantle minutely tuberculated, showing the form of the 

 internal aggregated particles of lime, the substitute of a shell-plate, reddish 

 fawn-color, with a central longitudinal interrupted darker band and a circular 

 marginal similar band, broken in front, where it is replaced by small, irregu- 

 larly disposed dots of same color; these dots occur also in the submarginal 

 band of light color. Body reticulated with darker colored lines, running 

 almost longitudinally, scarcely obliquely, toward the end of the tail, and con- 

 nected by obliquely transverse lines of similar color, the areas included in 

 the meshes of this network covered with crowded tubercles, as in Prophysaon 

 Andersoni, shown in Plate IX. Figs I, J. Tail cut off by the animal. (See 

 below.) Excepting its being of a deeper red, it agrees perfectly with Dr. 

 Gould's description. 



Mr. Hemphill writes of it : "I have to record a peculiar habit that is quite 

 remarkable for this class of animals. When I found the specimen, I noticed 

 a constriction about one third of the distance between the end of the tail and 

 the mantle. I placed the specimen in a box with wet moss and leaves, where 

 it remained for twenty-four hours. When I opened the box to examine the 

 specimen, I found I had two specimens instead of one. Upon examination of 

 both, I found my large slug had cut off his own tail at the place where I no- 

 ticed the constriction, and I was further surprised to find the severed tail piece 

 possessed as much vitality as the other part of the animal. The ends of both 

 parts at the point of separation were drawn in as if they were undergoing a 

 healing process. On account of the vitality of the tail piece, I felt greatly 

 interested to know if a head would be produced from it, and that thus it would 

 become a separate and distinct individual." The animal on reaching me still 

 plainly showed the point of separation from its tail (see Fig. A). The tail 

 piece was in an advanced stage of decomposition. I have noticed the con- 

 striction towards the tail in many individuals. The edges of the cut were 

 drawn in like the fingers of a glove, after the excision. 



The tail of the foliolatus having been cut off, I was unable to verify the 

 presence of a caudal pore from this individual. It was plainly visible in an- 

 other specimen from Seattle. 



In the large Olympia individual, the irregularly disposed particles of lime 

 in the mantle, of unequal size, seemed attached to a transparent membranous 

 plate. With care I removed this entire, and figure it. It is suboctagonal in 

 shape (Plate VIII. Fig. B). Under the microscope it appears that the par- 

 ticles of lime do not cover the whole plate; at many points they are widely 

 separated. This aggregation of separate particles is the distinctive character of 

 the subgenus Prolepis, to which foliolatus would belong if retained in Arion. 



