352 IV. S. NICKERSON. [Vol. XVII. 



(Hincks, '77) as occurring in the Gulf of St. Lawrence, but no 

 study of it has been made, nor has a satisfactory description 

 been published. Verrill ('79) has also mentioned Loxosoma as 

 occurring on the New England coast, but without identifying 

 the species or giving any description from which it could be 

 recognized. With these exceptions no representatives of the 

 genus have been known to occur outside of European waters. 

 During the summer of 1897 I found a species of Loxosoma 

 living in abundance upon the New England coast. To it, the 

 first member of this genus to be described from the western 

 hemisphere, I have given ^ the name " Loxosoma Davenporti," 

 in honor of the foremost American student of the Bryozoa, 

 who was also the first to recognize it as a new species, from a 

 mounted specimen sent him. A study of this form has re- 

 vealed several structural features not found in European spe- 

 cies, and incomplete studies of its development give promise of 

 novel embryological data. The present paper will be confined 

 to a description of the structural characters, leaving its embry- 

 ology to be described subsequently after the opportunity for 

 more thorough investigation. 



Orientation of Loxoso^na. — The terms "dorsal," "ventral," 

 "transverse," "longitudinal," etc., will be used in accordance 

 with the interpretation of the relations of the body given by 

 Harmer, '86 (not '85). According to this view, the antero-pos- 

 terior axis of the animal coincides with its longest diameter, 

 and a section perpendicular to this axis is a transverse section. 

 The ventral surface includes the whole inner face of the lopho- 

 phore, the side of the body and stalk toward which this is 

 turned, and the foot or surface for attachment. Ventral is, 

 therefore, essentially synonymous with anterior. The dorsal 

 (= posterior) surface is that between the distal extremity of the 

 lophophore and the posterior margin of the foot. 



Brief Statement of External Characteristics. — Loxosoma 

 Davenporti is a robust little animal between .75 mm. and 2.4 

 mm. in length when fully expanded, the stalk making up about 

 one-half of the total length. The average individual is about 



1 See Reports of Meetings of American Morphological Society, in Science (n.s.), 

 vol. vii, 1898, p. 220, and vol. ix, 1899, p. 366. 



