314 bulletin: museum of comparative zoology. 



regards provisionally as belonging to P. sedgwicki. This he believes 

 may really represent a distinct species, however, when known from 

 more extensive material. On the north several forms show a close 

 relationship of St. Vincent and Dominica to the more northern 

 islands; thus P. dominicae extends in varietal forms from Porto 

 Rico to Antigua and as far south as Dominica, while the varieties 

 of P. juliformis extend from Jamaica through St. Thomas to St. 

 Vincent on the south. 



Peripatus juliformis Guild, var. swainsonae Cockerell. 



Plate 2, figs. 1-2. 



I have had the opportunity of examining a large series of this 

 Jamaican species collected by Messrs. M. Grabham and Thomas 

 Barbour at Bath, Jamaica, and presented to the Museum of Compara- 

 tive Zoology by Dr. Barbour. There are 114 specimens in all, the 

 majority of them females, but with a good series of males. 



These have been examined to ascertain the amount of variation 

 in the number of legs, and the results are tabulated in figure 3a. 

 The number varies from 27 to 35 with 28 pairs as the mode for males 

 and 33 pairs for females, and in both sexes the modal number is far 

 more common than all the other numbers together. Since Bouvier 

 has recorded the number of legs in all the specimens of this species 

 which he has seen, I have added his data in dotted lines, and it will 

 be seen that these follow closely the solid lines representing the present 

 material. In figure 4a I have added the two curves together, and 

 believe that this represents quite closely the actual range of variation, 

 as the sum is based on nearly 200 specimens. It will be seen that there 

 is hardly any overlapping of the male and female polygons, so that the 

 sexes may be almost positively separated by the number of legs, the 

 males having less than 30 and the females over 30. 



The color of the present series of specimens is somewhat different 

 from that described by Bouvier for individuals from exactly the same 

 locality in Jamaica, and I suspect that the difference is due to the 

 length of time they have remained in alcohol. Bouvier describes 

 the color as grayish above, sometimes paler and delicately tinged 

 with greenish yellow, or sometimes darker and tending toward dark 

 gray. There is great variation in the shade, but all of the better 

 preserved and unfaded individuals have the dorsal surface very dark 



