PYCNOGONIDA OF NEW ENGLAND AND ADJACENT WATERS. 467 



anatomy and, in some cases, of their embryology. The systematic work 

 has, with few exceptions, been unsatisfactory and confusing, owing to 

 the paucity of generic and specific characters, the great variation of 

 some species, the difficulty of obtaining large series of specimens, and 

 the want of detailed descrix:)tions. Though the specific characters are 

 well marked, the general resemblance is so close in certain genera 

 {e. g., Nynqylion, FlioxicMUdium) as to render close examination neces- 

 sary for the projjer determination of the species. For this reason it is 

 quite impossible to determine, from the descriptions, to what species 

 some of the older names should be ai)plied ; and hence, as a rule, only 

 such references are given in the synonymy as refer to figures or full 

 descriptions. 



The North American species have hitherto received little attention. 

 Leach described an Ammothea from Carolina, and Stimpsou another 

 species of this genus from Puget Sound. Thomas Say described, in 

 1821, from Charleston, S. C, the genus AnapJiia, of which he had one 

 species {A. imllida) represented by three specimens. In 1853, Stimpson 

 enumerated five species in his " Invertebrata of Grand Manan," of which 

 four were described as new. In addition to these, three or four species 

 are mentioned, accompanied in some cases by brief notes, in papers 

 by Professors Yerrill, Smith, Packard, and others. The '■'■ Pasitlioe'''' 

 described by Dr. Gould (Proc. Bost. Soc. Nat. Hist., vol. i, p. 92) is inde- 

 terminable. With two exceptions, the species here described were fully 

 figured and characterized in a preliminary i)aper by the author, entitled 

 "A Synopsis of the Pycnogonida of New England" (Trans. Conn. Acad. 

 Sci., vol. V, pp. 1-26). 



The genera known to me are included in the following table, those 

 occurring on the New England coast being indicated by an asterisk. 

 It should be noted that the table is in part compiled from descriptions, 

 some of which are very imperfect. In cases where I have been unable 

 to find the exact characters, an interrogation mark is placed after the 

 name. There is need of a revision of the present genera, which can • 

 only be effected by the study of a large collection from all parts of the 

 world. 



I have been unable to ascertain the characters of the genus Gnamp- 

 torhynchus recently described by Bohm, and have therefore not included 

 it in the table. 



A. Antemife present and chelate. 

 a. Palpi present. {Nymjplionidce). 

 b. Auxiliary claws j)resent. 



(1). Accessory legs 11-jointed. Palpi 5-jointed *KympJwn Fabr, 



(2). Accessory legs 9-jointed. Palpi 8-joiutcd * Ammothea Leach. 



(3). Stigmata present (?) Accessory legs 3-4 (?) jointed. Palpi 3-jointcd. 



rhanodemits Costa. 

 hb. Auxiliary claws wanting. 

 (1). Accessory legs ll-jointed. Palpi 10-joiuted Dccolopoda Eights. 



