Boone, Crustacea, Cruise of "Alva," 1931 177 



Miers) ; Zanzibar (Pfeffer) ; Dar-es-Salaam (Ortmann) ; Mozam- 

 bique (Lenz). 



Material examined: One specimen, taken in coral, Falcon 

 Island, Palm Islands, Queensland, October 7, 1931. 



Technical description : Carapace typically stout and nine- 

 tenths as broad as long, depressed ; length from orbital angle to 

 posterior margin, 5 mm. ; width, 4.5 mm. ; rostrum, 3.8 mm. long 

 from tip to orbital angle, or almost three-fourths as long as the 

 carapace. The rostrum arises as a wide triangle between the eyes, 

 which narrows rather abruptly just anterior to the eyestalk and 

 proceeds from this point forward as a slender, acuminate triangle, 

 the apical third of which is quite stylus-like and which is dorsally 

 carinate, this sharp carina continuing posteriorly the entire length 

 of the rostrum, terminating abruptly in a rounded end proximally 

 on the base of the rostrum, with a small depression on either side 

 of the rostrum at the base ; this rostrum is directed straight for- 

 ward for the proximal two-thirds of its length, thence slightly 

 downward ; there are five acute, subequal, forward-directed teeth 

 in serial arrangement on the carinate dorsal rostral margin, the 

 proximal tooth being above and slightly in advance of the proxi- 

 mal margin of the scaphocerite, and the fifth, or distal, tooth being 

 subdistal to the acuminate apex ; there is but one acuminate tooth 

 on the inferior rostral margin and this is opposite the subdistal 

 fifth tooth of the upper margin. The rostrum extends beyond the 

 antennular peduncle by about three rings of the related flagellum, 

 or is equal to two-thirds of the length of the scaphocerite. There 

 is no supraorbital spine present, but the usual pronounced depres- 

 sion of carapace behind the lower side of the orbit. 



The abdominal terga are generically characteristic ; the third 

 segment is about two and one-third times the length of the second 

 segment, has the median region produced posteriorly and the pos- 

 terior median margin rounded ; the fourth segment is about two- 

 thirds as long as the third segment; the fifth segment is nearly 

 as long as the fourth ; the sixth segment is about one and one-half 

 times as long as the fifth ; the telson is one and three-fourths times 

 as long as the preceding segment, very narrowed, triangulate, 

 and dorsally carinate, with four pairs of articulated spines, in 

 submedian, longitudinal series ; the apex of the distal margin has an 

 acute tip, flanked by a pair of long, articulate spines, which project 

 beyond the telson. The uropoda are about one-fourth longer than 



