8 PROCEEDINGS OF THE NATIONAL MUSEUM vol.72 



Both pairs of gonopods simple, long and slender, the terminal 

 joint of each pair nearly straight; anterior gonopods directed for- 

 ward, with the last joint as long as all the preceding joints together; 

 posterior gonopods longer and more slender and reaching forward 

 between the anterior gonopods to their tips, the last joint longer 

 than all the other joints together. 



The type of Siphonophora is S. portoricensis Brandt. The orig- 

 inal specimens are in the Berlin Museum and show a tapering conical 

 head equaled or exceeded in length by a long slender beak. The 

 antennae are moderately crassate with the joints gradually thicker 

 from the base, joint 2 slightly longer than joint 3, joints 3 to 5 sub- 

 equal in length, joint 6 about twice as long as joint 5, and joint 7 

 very short and scarcely projecting beyond joint 6; the first segment 

 more than twice as long as the second and distinctly emarginate in 

 the middle. The repugnatorial pores are borne on large rounded 

 prominences which give the segments the appearance of being dis- 

 tinctly shouldered. A larger female specimen with YO segments 

 has the beak much longer than the head, and the head is smaller 

 and more abruptly narrowed than in the male specimen, which has 

 a shorter beak, scarcely longer than the head. 



SIPHONACME LYTTONI, new species 



Description. — Body small, very long and slender, twenty to thirty 

 times as long as broad, scarcely tapering at the ends; the segments 

 rather strongly convex. Motions in crawling very slow. Male with 

 78 segments, females with 88 and 121 segments. Length of male, 

 16 mm.; width 0.7 mm.; largest female 29 mm. long and 0.9 mm. 

 broad. 



Living colors. — ^Head, antennae, and first segment white ; segments 

 2 to 4 with a longitudinal median band of dull pinkish abruptly 

 broadened and divided at segment 5, becoming gradually paler to 

 the middle of the body and finally disappearing so that the last seg- 

 ments also are white. The beak is a pale waxy yellow, and the large 

 lateral sense organs of the antennae, on joint 5, appear as distinct 

 orange-yellow spots. 



Head subglobose-pyriform, abruptly contracted to a short, slender 

 beak piliferous to the tip, less than one-third as long as the mass of 

 the head; surface of head tuberculate and pilose, the beak smooth 

 with scattered large and small hairs. 



Gnathochilarium distinct, narrowly triangular, a group of large 

 bristles at the apex as long as the slender apical portion of the beak ; 

 median groove present, basal angles rounded, very close to the inser- 

 tion of the first pair of legs. 



