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



possessing two abductors and a very strong, thick and long adductor, the inner branch 

 having simple and very weak muscles. 



Notes are given (pp. 465-6) on the nerve-system as displayed in Goplana polonica and the 

 varieties of Gammarus puJe:i: The "auditory hairs" on the upper antennse of Callisoma 

 hranickii are minutely described, and from their hkeness in structure and nerve-apparatus 

 to the auditory hairs and auditory nerves of the Decapods, as described by Hensen, it is 

 argued that a like function may be reasonably attributed to these organs in the Amphipods, 

 notwithstanding Leydig's doubts on the subject. The plumose hairs of the last uropods 

 are not considered to have anything in common with the function of hearing. A detailed 

 account is given of the antennary nerves in OalUsoma hranicldi. 



In describing the so-called "calceoli," the author refers to the work of Dybowsky as showing in 

 agreement with his own observations that these organs are to be found sometimes on the 

 upper as well as the lower antenna?, and in the female as well as the male sex. He thinks 

 it clear that the " trumpet-mouthed auditory cilia " on the upper antennae of Gossea 

 microdeutopa, Sp. Bate, and the oval " auditory cilia " on the upper antennse of Batlujporeia 

 rolertsoni of the same author, are really " calceoli." 



In Callisoma branicliii the calceolus presents a thin-walled, flattened, pedunculate vesicle, nearly 

 of the same form as figured for Gammarus pulex and Gammarus nefjledus by de la 

 Valette, G. O. Sars and Leydig. A large circular ganglion-ceU lies close to the base of the 

 calceolus, but the entrance of the nerve into it could not be made out. In the peculiar 

 lanceolate calceoli of Gnp)lana piohmira, nerve-flbrillfe were traced right to the sharpened 

 rims of these organs, with a fan-Like distribution. The calceoli are here regarded as 

 apparatus for smelling in agreement with the view of G. 0. Sars. [This view had earlier 

 been advocated by de la Valette and by Bate and Westwood, Brit. Sess. Crust., vol. i. p. 87, 

 1863 ; H. Blanc would refer them to the sense of hearing.] 



In Ilyale jelskii, the author found on the front rim, both of the outer and of the inner lobe, 

 of the second maxillae three rows of bristles, each row consisting of differently formed 

 bristles. In the uppermost row no connection was found with the nerves, but in the lowest 

 and middle rows this connection was made out, and the suggestion is offered that the 

 lowest row are perhaps organs of touch and the middle row organs of taste. 



Numerous observations are given (p. 511 f.) on the intestinal canal and its api^endages. The 

 whole length of this organ appears to be sheathed in a layer of the adipose tissue (Leydig's 

 serosa). The muscular covering of the mid-gut consists chiefly of transverse threads, that 

 of the hind-gut of an outer layer of transverse, and of inner, thick, separate, longitudinal 

 muscles. The membrana propria of the mid-gut is very thin, that of the hind-gut thick, 

 consisting of a transparent, homogeneous matrix, including groups of spindle-shaped cells 

 which run out into thin, long processes at both ends. In the central part of the mid-gut 

 he believes that no cuticula or intima exists. [In the Caprellida;' Mayer (p. 147) find.'=, 

 apparently throughout, a fine, not chitinous, intima.] Between the mid- and hind-gut is an 

 outer projection and an inner, ring-shaped flap or valve, with its free edge directed back- 

 wards, so that what is passing through the body can easily go from the mid- into the hind- 

 gut, but nut easily on the reverse route. In Pallasea cancellus the hind-gut has six rows 

 of dilators (not to be confounded with sphincters). 



The appendages of the intestine are next discussed. The cascal diverticulum behind the stomach 

 is designated neck-gland (Nackendrtise.) To this expression Mayer takes exception as not 

 very appropriate, ilayer also remarks that in the Caprellidae there are at this part of the 

 intestine not one diverticulum only, but a pair. The muscles, cells and vesicles of the 

 liver-tubes are minutely described. The cylindrical glands, opening, according to the author, 

 at the beginning of the hind-gut, close behind the above-mentioned valve, are called rectal- 

 glands (rectaldrusen.) The view of G. 0. Sars that these cylindrical glands are homologous 



