102 Bulletin Vanderbilt Marine Mixseum, Vol. VI 



is by far the most comprehensive series of this species examined 

 by any one writer. Unfortunately this excellent small paper of 

 Dr. Kemp's was overlooked by Dr. Hansen in his report on the 

 "Siboga" Sergestidae, consequently these four species of Acetes, 

 including the new species Acetes insularis Kemp from the mouth 

 of the Rajang River, Sarawak, Borneo, discussed by Dr. Kemp, 

 are omitted from Dr. Hansen's monograph. 



The carapace is semitranslucent, slender, produced to a short 

 rostral crest, the upper margin of which is bidentate, in addition 

 to the small triangulate apex, which protrudes beyond the frontal 

 margin minutely. The supraorbital spine is well developed and 

 is approximately in line transversely with the posterior rostral 

 spine. The hepatic spine is well developed and set well back on 

 the carapace, about one-third of the total carapace length from 

 the margin. There is a pronounced strong groove, margined on 

 either side by a distinct ridge that arises below and a little behind 

 the hepatic spine about midway the length of the lower lateral 

 region and curves up a short distance and thence proceeds nearly 

 straight back to the posterior margin. 



The abdominal terga are slender, quite compressed. The sixth 

 segment is about twice as long as the preceding segment ; the telson 

 is three-fifths as long as the sixth segment, or half as long as the 

 outer blade of the uropoda, with a deep median groove for the 

 proximal two-thirds of its length ; the sides of the telson are con- 

 vergent to a sharp, triangular apex. The angular ending of the 

 lobe, defining the proximal end of the inferolateral margin, is 

 situated about two-fifths of the length from the base of the telson. 

 The uropoda are quite slender, the shorter, inner blade is two- 

 fifths longer than the telson and the outer blade is about twice 

 as long ; both have their greatest width proximally and each has 

 the two lateral margins quite convergent; the tip is quite nar- 

 rowed, rounded. The outer blade has the outer lateral margin a 

 little thickened, this part terminating in a small tooth, which in 

 adults is placed from 55 to 65 per centum of the total length, the 

 distal portion of the margin being ciliated. In young specimens 

 this ciliated area is shorter. 



The eye of the adult female is characteristically long, being 

 one-half as long as the carapace; the eye, measured from the 

 dorsal proximal border of the stalk to tip of the cornea, is 3.5 

 mm. long; the carapace is 7 mm. long, from tip of rostrum to 



