676 CRUSTACEA. 



metrical, uncovered by the carapax. Anterior antennae bifid, base 

 long, and first joint with lower apex much prolonged and the pro- 

 cess minutely spinulous within. Second antennae without a scale 

 at base. Abdominal feet natatory. Last segment of abdomen 

 truncate, without a barb either side of extremity, but set with 

 minute spinules. [Possibly young of some species of Eubranchiata 

 or Decapoda.] 



The Furciliae collected by the author were none of them apparently 

 mature. The thoracic members were but partly developed, and the 

 abdominal in many instances were rudimentary. Yet as we know 

 not where to refer them, they are for the present arranged here. 

 They are alike in the inner antennae, the base being long, and the 

 lower apex of the first joint prolonged, with an acute process as long 

 as the next joint. In this character, they resemble only the Cyrtopiae 

 among the species described, but unlike them the eyes are symme- 

 trical, and the extremity of the abdomen has not the barb either side 

 which characterizes the Cyrtopiae, Euphausiae, and allied species. The 

 two branches of the inner antennae, as far as observed, consist each of 

 only one or two joints, often not longer than the apical joint of base ; 

 and to this simple furcation of the summit the name of the genus 

 alludes. The spinules upon the truncate apical margin of the last 

 abdominal segment are longer at the angles, and of even length along 

 the middle. The exterior antennae have also a bifid extremity, the 

 branches being one or two-jointed in the species examined. The tho- 

 racic and abdominal appendages are without branchiae. The latter, 

 when fully developed, have the usual natatory form. 

 The species were mostly found in the open ocean. 



FuRCILIA MACROPHTHALMA. 



Carapax acute" rostratus, posticd excavatus et ad angulos rotundatus rostro 

 oculisfere longiore. Oculi permagni, orbiculati, thorace parce angw- 

 tiores. Basis antennarum irdernarum prmlmigus, carapace vix bre- 

 vior; processus articuli primi articulo proximo brevior. Segmentum 

 abdominis posticum lamellis caudalibus dimidio fere brevius, truncatum, 

 nudum. 





