MABINE ISOPODS FROM THE PHILIPPINE ISLANDS. 



37 



Genus PSEUDIONE Kossmann. 



Pseudione fibriata, sp. nov. 



Body of adult female oblong-ovate, more or less asymmetrical, 8 mm. : 14 mm. (includ- 

 ing abdominal appendages). Color, in alcohol, yellow. 



Head large, deeply immersed in the first thoracic segment and with a rather wide 

 frontal border. Eyes absent. First pair of antennae composed of three or four arti- 

 cles, the first of which is the largest; second pair of antennae composed of five articles. 



All seven segments of the thorax distinct. Lateral bosses are present on the first 

 four segments. Lateral to these are the pleural plates, which occupy the anterior 

 half of the lateral margin and are drawn out in irregular branching processes. The 

 posterior half of the lateral margin is also drawn out in numerous finger-like processes. 

 The last three segments have 

 the lateral margins produced 

 in finger-like processes, which 

 in turn are branched. 



All six segments of the 

 abdomen are distinct, the 

 sixth or last segment being 

 very small. The first five are 

 provided with large leaf-like 

 pleural plates, which are 

 tuberculate. The sixth seg- 

 ment has no pleural plates. 

 There are five pairs of double - 

 branched leaf-like pleopoda, 

 the margins and surfaces of 

 which are tuberculate. The 

 uropoda are attached to the 

 terminal segment and consist 

 of a pair of simple leaf-like 

 appendages, also tuberculate. The five pairs of incubatory plates overlap in the 

 middle of the ventral side of the thorax and completely inclose the marsupial 

 cavity. The seven pairs of legs are prehensile and have the basis furnished with a 

 high carina. 



Two males in the cryptoniscian stage and one immature male probably in the 

 microniscus stage were taken. Only one adult specimen, a female, was collected, 

 at station 5126, Nogas Island (W.) S. 26° 30 / E., 11.75 mi. (10° 34' 45" N., 121° 47' 30" 

 E.), at a depth of 742 fathoms, in soft green mud. Type, catalogue number 40924, 

 United States National Museum. 



Pseudione retrorsa, sp. nov. 



Body of adult female oblong-ovate, 9 mm.: 14 mm. (including abdominal append- 

 ages). Color, in alcohol, yellow. 



Head deeply immersed in the first thoracic segment and with a narrow frontal border 

 becoming wider at the sides. Eyes absent. First pair of antennae composed of four 

 articles; second pair composed of five articles. 



All seven segments of the thorax distinct. Lateral bosses are present on the first 

 four segments. Lateral to these are the pleural plates, which occupy only about half 

 of the lateral margin. The pleural plates of the last three segments occupy almost 

 the entire lateral margin. 



All six segments of the abdomen are distinct, the sixth or terminal segment being 

 very small and rounded posteriorly. Pleural plates are developed on the first five 

 segments, but are not present on the sixth. There are five pairs of double-branched 



Fig. 34.— Pseudione fibriata. a, Female, X2j 

 stage, X41; c, seventh leg of female, 



b, microniscus 

 X20|. 



