426 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



17. Genus PYROCYPRIS Muller, 1890. 



Cypridina Authors, 1852 (Dana), 1S68. 



Pyrocypris G. W. Muller, Zool. Jahrb., Abth. Syst., V, 1890, p. 231, pl.-xxv, 

 • figs. 1-8 ; pi. xxvi, figs. 10, 12, 16, 19 ; pi. xxvn, figs. 1, 2, IS, 24, 34-37.— 



Brady, Trans. Zool. Soc. Lond., XVI, 1902, p. 1S5.— G. W. Muller, 



Ostraeoda, Abdr, aus Wiss. Ergeb. der deutscb. Tiefsee Expedition 



" Valdivia," 1S9S-99, 190G, p. 107. 

 Eupathistoma Brady, Trans. Zool. Soc. Loud., 1898, XIV, Pt. 8, p. 437, pi. 



xliv, figs. 21-26. 



Shell membranous, about 2 mm. long, and produced posteriorly to 

 form a prominent rounded beak or process. 



Especially characteristic is the upper lip, which Muller a believes 

 serves as a phosphorescent organ. It is unusually well developed to 

 form six finger-like processes (Plate LXIV, fig. 5), the two anterior 

 unpaired, and four are in pairs, of which the two posterior ones are 

 the longest. It is always peculiarly pigmented with a dark-colored 

 pigment which presumably possesses the power of producing phos- 

 phorescent light by chemical means. 6 



Rudimentary branch of the second antennas similar in both sexes, 

 hardly noticeable, and with five seta?. 



Furca always with nine toothed spines, of which the second is im- 

 movably fixed with the furcal plate. Vermiform limb with a termi- 

 nal armature of from three to five unequal slender claw-like seta?, 

 all curved to one side. Brady c figures P. americana as having a furca 

 with but seven spines or spine-like seta?. This is undoubtedly an 

 error, probably due to poor specimens. 



Commonly caught at night with a surface net in tropical seas. 

 Many instances are on record of hauls containing as high as 15,000 

 to 20,000 individuals. Sexual. Heretofore recorded as occurring off 

 the American coast only by the Galatea expedition, September 10, 

 1875, the species P. americana being reported off the west coast of 

 Central America. 



Brady believes this genus intermediate in character between Cypri- 

 dina and Pltilomedes. 



28. PYROCYPRIS AMERICANA G. W. Muller. 



Plate LXIV, figs. 1-5. 



Pyrocypris americana Muller, Zool. Jahrb., Abth. Syst., V, 1S90, p. 233, 

 pi. xxv, fig. 3. — Brady. On new or imperfectly known Ostraeoda, chiefly 

 from a collection in the Zool. Museum, Copenhagen, L902, p. 1S5, pi. xxi, 

 figs. 14-19. 



Dimensions. — Length, 1.55 mm.; height, 0.85 mm.; breadth, 



0.5G mm. 



" Xene Cypridinidon, Zool. Jahrb. Abth. Syst., V, 1890, p. 231. 

 6 Watanabe, II.. 1897, Jour. R. Micr. Soc, Pt. 5, p. 384. 

 c Trans. Zool. Soc. London, XVI, 1902, p. 185. 



