REPORT ON THE CRUSTACEA MACRURA. 



713 



The first two somites of the pleon are short ; the third is very long, and has the posterior 

 dorsal portion placed at a right angle to the anterior portion, the angle being posteriorly 

 produced to a large curved tooth or hook ; the fourth and fifth somites are shorter than 

 the third by more than half its length. The sixth is very long and narrow. 



The telson is about three-fourths of the length of the sixth somite and terminates in 

 a point tipped with a few hairs. 



Habitat. — October 27, 1874, near Samboangan, Philippine Islands. One specimen. 



The carapace corresponds in length with the anterior portion of the pleon as far as 

 the dorsal angle on the third somite, or about one-fourth the length of the entire pleon ; 

 it is anteriorly produced to a rostrum that is about one-third the length of the carapace, 

 and armed with two sharp teeth on the crest, or frontal region, and smooth on the lower 

 margin. The fronto lateral angle of the carapace is produced to a sharp tooth. 



The pleon has the first two somites short, but laterally almost as deep as the carapace, 

 and has the fronto-lateral angle anteriorly produced to a sharp tooth. The third somite 

 appears quadrate when viewed laterally, the dorsal surface being produced near the 

 middle, so that the anterior and posterior portions are situated at right angles to each 

 other, and the angle formed by the two is posteriorly produced to a large tooth-like 

 process that is curved posteriorly downwards, and like the two preceding has the fronto- 

 lateral angle produced to a sharp tooth. The fourth somite articulates with the third at 

 a right angle with the anterior somites ; it is less deep and narrower than those anterior 

 to it. The fifth somite is a little smaller than the fourth, and the sixth is three times 

 as long, much narrower and less deep, and is produced on each side posteriorly to 

 a small tooth. 



The telson is long, tapers to a point, and equals about three-fourths the length of 

 the sixth somite. 



The ophthalmopoda are very large and orbicular, forming with the ophthalmus a 

 nearly spherical body, that reaches beyond and above the rostrum, and projects laterally 

 on each side, the ophthalmus occupying about the anterior third. 



The first pair of antennae has the peduncle three-jointed ; the first joint is not quite 

 as long as the ophthalmopod, and is slightly excavate to correspond with it ; the second 



(200L. CHALL. EXP. — PART LII. 1887.) 



Fff 90 



