600 BULLETIN 82, UNITED STATES NATIONAL MUSEUM. 



tecting the channel between itself and Roscoff. As a result of these conditions 

 the littoral fauna is here particularly rich. 



For two years in succession (in 1868 and 1869) he passed a part of the summer 

 engaged in zoological research in this locality, one of the richest on the French 

 coast. 



At low tide when one goes directly northward down from the Eoscoff church 

 to the beach one sees ahead large granitic peaks, which, never covered by the sea, 

 form islets even at the highest tides. At the east and at the right are the two 

 Bourguignons, at the west and left Green Island, and more distant in an easterly 

 direction some rocks covered at high tide among which are Meinanet and Rolas. 



Between these reefs and in the channel the low tide exposes broad and beautifid 

 fields of eelgrass (Zostera) and sandy areas covered with stones, both of which are 

 inhabited by numerous species of animals, by a great variety of ascidians, both 

 simple and compound, by brj^ozoans, sertularians, sponges, especially calcareous 

 sponges, echinoderms, synaptas, lucernarians, caryophyllias, numerous actinians, 

 planarians, borlasias, very numerous naked and shell-bearing mollusks, etc., which 

 abundantly compensate the zoologist for the difficulties encountered in searching 

 the shores. 



The two zones which the algae habitually occupy, the higher characterized by 

 Fucus vesiculosus and F. serratus and the lower by Laminaria, are at Eoscoff 

 sharply separated by Uimanthalia lorea, which in this region is used, under the 

 name of fiber, as manure for vegetables. The Himanthalia zone is uncovered at the 

 spring tides, but is not entirely dry except at the lowest water, when the Laminana 

 below is itself accessible. This description of the local conditions is necessary, 

 for one has no idea of the difficulties attending a zoological reconnaissance over 

 the rocks covered with Himanthalia until one has become entangled ifi these long 

 bundle of lacerating fronds which conceal the holes among the rocks and slip 

 away so easily from beneath one's feet. Almost nothing can be obtained here, 

 for progress is not only extremely difficult, but becomes even dangerous on account 

 of the numerous tumbles. 



In the Laminaria zone the search for animals is at the same time easier and 

 more productive; but the point of especial interest is the presence of this seaweed 

 in the Himanthalia zone and the curious fact that this plant sometimes abandons 

 the deeper levels and rises for a considerable distance toward the high-tide mark. 



At the lowest tides the water flowing from the land excavates channels in 

 the sandy patches and in the grassy areas, forming streamlets which are often 

 of considerable size and swiftness. West of Green Island and the Bourguignons 

 these channels are numerous, and it is in them that the seaweed ascends and where 

 the pentacrinoids of Ayitedon are found abundantly. If in these streamlets at low 

 tide the ramifying roots of the seaweed are detached, the bushiest ones being 

 chosen and pulled out close to the ground, it is almost certain in the months of 

 July and August and in the beginning of September that pentacrinoids will 

 be found. 



When the roots of the seaweed are much branched the rootlets by their rami- 

 fications form a bushlike growth in the midst of which Antedon Miida is especially 



