Boone, Crustacea, Cruise of "Alva," 1931 93 



equally spaced, dividing the remainder of the lower rostral margin 

 into three parts. 



The large male has the rostral formula -|, and the very 

 acute apex extends beyond the scaphocerite for a distance equal 

 to the length of the second peduncular article of the antennulae. 

 The extra spines are distributed on the distal portion of the 

 rostrum. 



The second male has the rostral formula |, the extra spines 

 being distributed on the distal portion of the rostrum, the sixth 

 inferior spine being very near the tip. 



The carapace of the male is smooth, has no orbital spine and 

 no true angulation of the carapace at this point. The antennal 

 spine is acute above the rounded antennal margin and is continued 

 backward as a ridge which vanishes opposite and anterior to the 

 hepatic spine; above this ridge and parallel to it is a distinct 

 sulcus that vanishes beneath the hepatic spine ; there is no inferior, 

 or subhepatic, sulcus or ridge. The upper margin of the antennal 

 sulcus is defined by a moderate carina from a point opposite the 

 hepatic spine for almost two-thirds of the distance to the frontal 

 margin of the carapace ; this ridge is slightly oblique, subparallel 

 to the antennal ridge. The cervical groove is confluent anteriorly 

 with the hepatic and curves backward above the hepatic tooth, al- 

 most halfway to the rostral carina. The fact that these antennal 

 and hepatic spines are weaker, the sulcus less deep and the defining 

 ridges less salient and that there is no subhepatic ridge present, 

 render Peneus indicus distinct from P. semisulcatus de Man. 



The posterior three-fifths of the fourth abdominal segment 

 and the entire fifth and sixth segments are carinate in the median 

 dorsal line, this carina terminating in a small, distal tooth on the 

 sixth segment. The sixth segment is equal in length to the telson. 

 The telson is triangulate, with a strong median dorsal groove ex- 

 tending to near the tip ; the apex is acute ; the distal half of the lat- 

 eral margins is finely ciliate. The uropoda have the outer blade pro- 

 jecting nearly half its length beyond the telson; narrowly ovate, 

 with the tip unequally rounded; the inner blade is shorter and 

 narrower with the tip even more unequally rounded, the inner side 

 being somewhat obliquely truncated toward the outer tip and 

 slightly rounded. 



The eye has a distinctive node on the outer dorsal, frontal side 

 of the stalk ; the cornea is broad, reniform, and well protected. 



