IMPEKFECTLT-KNOW]^f OSTEACODA. 185 



of the shell marked with distant circular pittings, in the intervals of which are 

 minute puncta. Length 3-7 mm. The antenna! swimming-setse, excepting the first, 

 are densely plumose and without spines, the first much smaller, imperfectly jointed, 

 non-plumose, and bearing several short but sharp marginal spines ; secondary branch 

 of the antenna simple, two-jointed, and bearing a long terminal seta (fig. 13). The 

 vermiform limb has a simple terminal claw (fig. 14), beneath which is a large quadrate 

 gap, and following this a still larger unjointed space beyond the ringed portion of 

 the limb. 



Hah. Java Sound, in a depth of 8 fathoms. One female only. 



Genus Pyjrocypris G. W. Miillen 

 { = EupatMstoma G. S. Brady.) 



rYROCYPEis AMERICANA G. W. Miiller. (Plate XXI. figs. 14-19.) 

 Pyrocypris americana G. W. Miiller, Neue Cypridiniden, torn. cit. p. 233, pi. xxv. fig. 3. 



Shell, seen from the side, elongated, obliquely subquadrate, about twice as long as 

 broad (fig. 14); anterior extremity narrow, beak short, obtusely pointed in front, 

 acutely below, antennal notch small and narrow ; posterior extremity produced into a 

 prominent rounded beak ; dorsal margin gently arcuate, sloping steeply behind, ventral 

 boldly rounded in front, thence gently curved throughout its whole length ; shell 

 smooth, thin, chitinous. Length 2 mm. Secondary branch of the antenna (fig. 16) 

 reduced to a fascicle of five short setaj ; mandibular foot nearly as in Cijpridina (fig. 17), 

 bearing an ovate setiferous lobe and digitiform process ; vermiform limb armed at the 

 free extremity with three slender curved claw-like setae (fig. 18), caudal lamin« 

 (fig. 19) having four strong pectinated ungues and three shorter spine-like setae. 

 The first long seta of the antennule is dilated bulbously at the base (fig. 15), and bears 

 a short tubular (\) barb («) on the distal side of the bulb. The labial papillie 

 (phosphorescent organs of Miiller) are not unlike those of P. chiercldce [Eupathistoma 

 nutans Brady), which have been previously figured and described by me as 

 sense-organs. 



1 do not fully understand the nature of the bulbous enlargement at the base of the 

 antennular seta, but it has an appearance somewhat similar to the poison-glands of the 

 Cytheridffi, and I would suggest that it may have a similar function, the barb-like 

 appendage being its efferent duct. 



Taken by the 'Galathea' Expedition, Sept. 10th, 1875. 



Specimens from this collection have been identified by Dr. G. W. Miiller as 

 belonging to Eyrocypris americana., which species was described from specimens taken 

 off the west coast of Central America. 



