292 COLE 



Family PYCNOGONID^E. 

 Chelifori and palpi both absent ; ovigera present in the male only 



Genus Pycnogonum Briinnich (1764). 



Trunk stout and square-set. Ovigera small, present only in the male, 

 9- or lo-jointed. Legs comparatively short, stout, tapering. First tarsal 

 joint small; claw powerful; auxiliary claws usually absent. 



Remarks. There seems to be a disagreement among authors as to 

 whether in this genus the ovigera are 9-jointed or lo-jointed. This is 

 probably due to the fact that some count the terminal claw as a joint, 

 while others do not ; but as it differs from the others only in being smaller 

 and more chitinous, I see no reason why it should not be considered a 

 joint the same as the terminal claw of the legs. 



PYCNOGONUM STEARNSI Ives. 

 Plate xiv, figs. 13-15; plate xxvi, fig. 10. 

 Pycnogonum stearnsi IVES, '92, p. 142, pi. x, figs 1-4. 



Trunk broad, somewhat depressed ; lateral processes with scarcely any 

 interval between them. Each trunk segment with a prominent tubercle 

 at its posterior border on the mid-dorsal line (considerably smaller on the 

 last segment), and a somewhat smaller tubercle on the outer edge of each 

 lateral process. First trunk segment about two thirds the length of the 

 proboscis, slightly constricted just ahead of the lateral processes ; second 

 and third segments each equal to the portion of the first back of the con- 

 striction; the fourth somewhat shorter. Posterior borders of the 

 segments slightly elevated. 



Caudal segment clavate, or nearly cuneiform, truncated at its ex- 

 tremity, sometimes slightly swollen in the middle ; somewhat longer than 

 the fourth trunk segment, about equal to the third. The anus is a 

 longitudinal slit on the ventral side of the caudal segment near the tip. 



Eye tubercle bluntly conical, placed just behind the constriction of the first 

 segment ; eyes black or dark brown, distinct, or in some cases indistinct and 

 without pigment ; the posterior pair usually farther apart than the anterior. 



Proboscis subcylindrical, slightly swollen at or a little anterior to the 

 middle ; somewhat longer than the first trunk segment. 



Ovigera (pi. xxvi, fig. 10) small and rather slender; lo-jointed, the last 

 joint a strong, straight, or nearly straight, claw. The joints do not 

 diminish gradually in length; the first, second, fourth, seventh, and 

 eighth are approximately as long as broad, while the others are propor- 

 tionately longer. The diameter does not decrease greatly until the ninth 



