759 THE AMERICAN NATURALIST [VoL. LI 



listed by Coe, but is also common among the masses and sheets 

 of matted sea weeds (Laurentia, Valonia, Halimeda, and asso- 

 ciated plants) which cover the bottom of Fairyland Creek. 

 Specimens were also obtained from under rocks situated a few 

 feet beneath low-water level, in muddy bays bordered by man- 

 groves, such as Tucker's Bay in Harrington Sound. The indi- 

 viduals collected in these places embraced white forms, some 

 with a tinge of pink, others decidedly pink (as in the "pale" 

 form figured by Coe, 1904, PL 1). They were 30-60 mm. in 

 length, and some contained embryos. 



In June and in July young Geonemertes were gotten among sea 

 weeds in Fairyland Creek ; these were 6-12 mm. in length. They 

 were identified principally through the microscopic examination 

 of the stylets and other organs. The stylets and stylet basis in 

 these young specimens were of the juvenile type for this species, 

 as figured by Coe (1904, PI. 25, Figs. 21, 24, 25). These young 

 specimens were in some cases pure white, in others tinged with 

 "smoky brown." I found no pinkish specimens less than 30 

 mm. in length. 



The observations upon the specimens of this species inhabiting 

 salt water indicate, as Coe concluded from his study of the land- 

 living individuals, that liberation of the young occurs in June 

 and in July. My largest examples of G. agricola from the water 

 were obtained in the spring. 



Large specimens of G. agricola are negatively phototropic, the 

 ocelli occupying the region of the body most sensitive toward 

 light. They orient away from the light with diagrammatic pre- 

 cision. This response leads to their being found, during the 

 day, under stones and about the roots of algae. 



It is hardly possible to credit the view that G. agricola has 

 extended the variety of its habitats during the brief time since 

 Coe's studies were made (1903) ; it is therefore necessary to 

 believe that this species of nemertean is not only terrestrial in 

 the proper sense, but truly marine as well. There seems no 

 good ground upon which to distinguish and separate the indi- 

 viduals found respectively on land, in the intertidal zone, and 

 definitely in the sea water. The terrestrial "variety" may then 

 be regarded as having originated, perhaps not so very long ago, 

 from the form which is undoubtedly marine unless one is pre- 

 pared to believe that, introduced as a terrestrial form, it has at 

 some time secondarily taken to the sea after a protracted evo- 



