114 THE VOYAGE OF H.M.S. CHALLENGER. 



and much harder than in its congeners, resembling a coat of mail, whence the specific 

 name ; back carinate, the segments increasing in length from the first to the tenth, from 

 whence they decrease ; and beginning with the third or fourth, are produced in sharp and 

 strong points directed backward : lateral lobes oblong, enlarging from the first to the 

 fourth segment, and decreasing to the seventh ; those of the three first caudal segments 

 are larger than those of the body, and are acuminate ; head produced into a strong, arched, 

 carinate, and sharp-pointed rostrum, curving down between the antennas; eyes large, 

 black, lateral, prominent and reniform ; beneath the eyes is a small lateral lobe ; antBunas 

 four-articulate, the upper pair having a small seta at the base of the fourth articulation ; 

 legs fourteen, two first pair with a large compressed monodactyle hand, those of the 

 anterior pair being smaller than the others ; third and fourth pairs of the same length as 

 the preceding, slender, terminating in a nail ; the three posterior pair directed backward, 

 similar in formation, but differing in size, the middle and longest pair being as long as the 

 body, and the seventh pair shorter tlian the fifth, all terminating in a nail ; colour in some 

 individuals pale, in others varied red and white." He points out that it differs from 

 Oiiiscm serrutus of O. Fabricius, from Gaminarus carinatm of J. C. Fabricius, and from 

 GammarelliLS pulex of Herbst. Atylus carinatus is mentioned as the name given by Leach 

 to the species Gammarus carinatus. 



Sabine next gives "Gammarus Sabini. Leach in Boss's Voyage, Ed. 8vo., Vol. 2, page 178. 

 G. segmentis dorsalibus postice falcato productis, capite inter antennas acumiue minuto. 

 Plate 1, fig. 8-11. On the shores of Baffiu's Bay, but not met with in the Polar Sea: 

 the head of this species which terminates in a point between the antennae, instead of 

 being produced in a rostrum, readily distinguishes it from the preceding species, and has 

 been added to the specific character assigned by Dr. Leach, in whose arrangement it was 

 unnecessary, the formation of the head making part of the character of the genus." 



The next species, "Taliteus Edvardsii, T. Rostro corniformi, antennis subsequalibus, corpore 

 ovato depresso, cauda compressa tricarinata spinosa. Plate II, fig. 1-4.," though here described 

 as new, is the Oniscus aeuleatus of Lepechin, now Ehachotropis aculeatus. The remarks 

 which follow the description bear upon classification. " In conformity," the author says, 

 "with the arrangement which is followed in the present account, this species has been 

 considered a Talitrus, as the inferior antennae are somewhat longer than the superior ; this 

 character is, however, by no means remarkable either in this species, or in some others, 

 which are distributed by it into the respective genera of Talitrus and Gammarus ; if a 

 subdivision be desirable in the well-defined and natural genus comprehending aU these 

 animals which so nearly resemble each other in general appearance and habits, the 

 prolongation of the anterior part of the head into a rostrum, would seem preferable to a 

 distinction founded on the relative length of the antennae, which in many of the species 

 are so nearly the same ; or, the genus Talitius might be limited to those species in which 

 the superior antennae are very short, not exceeding the length of the two first articulations 

 of the inferior pair." He adds that " this species has been named in compliment to John 

 Edwards, Esq., surgeon of the Hecla." 



The remaining species " Talitrus Ctane.^. T. capite obtusissimo, antennis subsequalibus, corpore 

 latiore, pedibus quatuor anticis inunguiculatis. Plate 1, fig. 12-18.," was taken "parasitic 

 on the Cyanea Arctica, the individuals varying in length from two to eight-tenths of an 

 inch : colour pale yellowish red, sprinkled with innumerable minute spots of deeper red ; 

 in about half the specimens, the number of which was considerable, the antenuie were 

 equal in length to the five first segments of the body ; in the others they wore scarcely 

 one-fifth as long, but otherwise similar; there was no olher perceptible difference in the 

 specimens." The eyes are "extremely large, lunate, of a brownish red colour." In the 

 further course of the description he mentions " legs fourteen, the four anterior equal and 



