71 



as the carinate part of the 5''> and 273-times as long as broad; the pleura of the 4'i> and 5"' 

 somite are separated from the terga by an obtuse ridge or crest, that continues on the 6''\ 

 running on it nearly twice as far distant from the lower as from the upper margin, though 

 gradually fading away on the middle. In the cited figures 5 and 6 of Acaiith. Batci Faxon 

 the telson appears hardly longer than the 6"i somite and even shorter than the endopodite of 

 the caudal fan; in Acanth. Sibogae, however, the telson is almost one and a half as 

 long as the 6'^ somite, the telson being in the larger specimen 11 mm. long, the a"' somite 

 8 mm., while in the other specimen these numbers are 10,5 mm. and 7,5 mm. The telson that 

 ends posteriorly in an acute spine, reaches, beyond the endopodite of the caudal fan, almost 

 to the end of the e.Kopodite and is grooved longitudinally from the terminal spine fo near the 

 base-, the groove is rather deep and ridged anteriorly, the ridge proceeding from the anterior 

 end of the groove almost to the middle. There are 3 or 4 pairs of very small spinules on the 

 lateral borders of the telson, the anterior pair situated just in the middle; the terminal spine 

 of the telson is flanked on each side by 3 spines, of which the middle one is the longest, twice 

 as long as the median spine, and reaching to the end of the outer plates of the caudal fan. 



Corneae reddish brown, small, but one-fourth as long as the rest of the eyestalk and some- 

 what less broad than the latter; they are hemispherical, but their posterior margin runs obliquely 

 with regard to the longitudinal axis of the eyestalk. An ocellus seems to be wanting, but there is a 

 blunt, though prominent ocular papilla on the inner side, just behind the cornea and directed inward. 



Antennular peduncle reaching almost to the middle of the antennal scale, basal article 

 almost as much longer than the eyestalks as the corneae are long, stylocerite acuminate, some- 

 what shorter than the eyestalks; flagella broken off; the upper outer one at base much broader 

 than the lower. 



Basal article of antennal peduncle with a small spinule on the lower margin ; scaphocerite 

 almost 3-times as long as broad, the outer border slightly convex, terminal spine shorter than 

 the oblique distal end of the scale; flagellum wanting. 



Mandibles (Fig. \'i d) imperfectly cleft, the incisor process 3-times as broad as the molar 

 process and armed with 8 or 9 brownish red teeth; the four first teeth, commencing from the 

 outer side, gradually increase in length, the 41*' being the longest of all the teeth with which 

 this process is armed. Second joint of mandibular palp a litde more than one and a half as 

 long as 3''<i joint. The two inner distal lobes of the second maxilla (Fig. 17^) are narrow^ and 

 project considerably beyond the basal lobe, while of the two distal lobes the anterior is one- 

 fourth broader than the other. 



Endopod of i*' maxilliped composed of 3 segments; the 2"'' segment, which is about 

 4-times as long as broad in the middle, is aY^-times as long as the 3'''^ or last and about 4-times 

 as long as the basal joint. The outer plate is a litde longer than the endopod, its distal margin 

 is regularly rounded and the inner margin is reflexed at nearly right angles longitudinally 

 (F'ig. 17/). The terminal joint of the 2"'^ maxilliped (Fig. 17^) is obliquely articulated with the 

 penultimate or 6''' joint and the length of the 4''', that is twice as long as its dista! margin is 

 wide, measures three-fifths the length of the two last joints taken together. The ^^^ joint, finally, 

 which is as long as wide, is auriculate at the inner side, while the outer margin is half as long as 



