REPORT ON THE CRUSTACEA MACRURA. 413 



The specimens taken north of New Guinea have the. rostrum short, as shown in 

 Kroyer's figure. 



SI rgestes lacmiaius, Kroyer. 



Sergestes laciniatus, Kroyer, Monograph. Fremstilling af Krseb. Sergestes, pp. 58, 66, Tab. v. 

 fig. 15, a-e. 



"Rostrum straight, rudimentary. 



" Ophthalmopoda reaching nearly to the extremity of the first joint of the peduncle of 

 the first pair of antennas, clavate; ophthalmus very distinct from the pedicle, very 

 short, being about the fourth or fifth of the length of the ophthalmopod, and nearly twice 

 as long as broad. 



" First pair of antennas has the peduncle a little shorter than the carapace ; first joint 

 subclavate, and nearly as long as the second and third together ; the second distinctly 

 loiioer than the third. 



O 



" Second pair of antenna? having the last joint of the peduncle sublinear, reaching to 

 marly half the length of the linear scaphocerite. 



" Second pair of gnathopoda a equal in length to nine-tenths of the entire animal. 



" Sixth somite of the pleon a fifth of the length of the animal, or equal to the first, 

 second, and third somites united (much longer than that of the fourth and fifth somites 

 together), and twice as long as broad. 



" Pleopoda long and slender ; basal joint of the fifth pair four times longer than broad. 

 Rhipidura having the external branch furnished with a rudimentary sharp point on the 

 outer margin, situated anterior to the middle." 



Habitat. — Greenland (Kroyer). 



Observations. — This species does not appear to differ from Sergestes corniculum in 

 any marked feature. According to Kroyer the chief distinction lies in the length of the 

 lustrum, which is rudimentary in Sergestes laciniatus and well defined in Sergestes 

 <-<>n<i<-nh<ni, and in the ophthalmus being more distinct from the stalk in the former 

 than in the latter. The author gives no figure of the animal as a whole. 



I can recognise no specimen in the collection of the Challenger that corresponds with 

 this description. 



Sergestes ancylops, Kroyer (PI. LXXV. fig. 2). 



Sergestes ancylops, Ejbyer, Monograph. Fremstilling af Krab. Sergestes, p. 46, Tab. iii. 

 fig. 8, a-e. 



" Rostrum small but distinct. 



" Ophthabnopoda generally much longer than the first joint of the first pair of antenna?, 

 angular, with the pedicle slender, straight, or nearly so, with long ovate ophthalmus. 



1 Pes maxillaris tcrtius longitudine j fl totiiis animalis sequans (vide note, p. 411). 



