1732 



THE VOYAGE OF H.M.S. CHALLENGER. 



furnished with nucleoli. The hexagonal epithelial cells 

 from various parts are figured by Claus, Der Org. der 

 Phronimiden, 1879. In some Amphipoda these cells are 

 very clearly visible in the pellucid skin. 464, 489, 562. 



Epizoaires (1*1, upon, (£a, living creatures), 94. 



Erioftalmi, 145, 152. 



Euryhaline {evpvs, wide, a\s, salt), 421. 



Eurytherm (evpvs, wide, depfiy, heat), 421. 



Exappendiculate, applied to the upper antennae when without 

 a secondary flagellum. 



Exochnata (efw, without, and -yyaBos, a jaw), 64. Latreille, 

 Hist. Nat., t. v. p. 151, says "the Kleistagnatha have 

 the palps broad and short, while the Exochnata have 

 them narrow, elongated, in form of arms or true palps. 

 The former have more resemblance to maxilla?. Fabricius 

 in applying two denominations to like objects, of 

 slightly different form, has been able to establish two 

 Orders, but the distinction is little tenable, not being 

 founded in nature." 



Exopodite (€|u, without, iroiis, a foot). See Endopodite. 



Exuviation (exuvia?, what is shipped from the body, a cast 

 skin), also called Ecdysis, the periodical process of 

 casting the skin, which is essential to growth in the 

 Amphipoda as in other Crustacea, 67, 153, 195, 290, 

 333, 474. See Cuticle, and compare also Brit. Sess. 

 Crust., vol. i. p. xxv. 



Eyes, 139, 154, 201, 260, 270, 327, 372, 383, 386, 423, 449, 461, 

 471, 474, 475, 480, 481, 486, 490, 495, 509, 553, 559, 

 597, 1638, 1651. 



Facetted, an expression applied to the transparent cuticle or 

 cornea over a compound eye, when the cornea is divided, 

 by a slight modification of its substance along the 

 dividing lines, into square or hexagonal spaces. The 

 cornea in the Amphipoda is said as a rule to be externally 

 smooth, not facetted, 154, 260, 471, 474, 480, 481, 516, 

 597, 1638. 



Fangorgane, grasping instruments, 274, 477. 



Fausses pattes, or pates, 95, 139, 186, 189. See Pleopods and 

 Uropods. 



Femur (in Latin, the thigh), 34, 49, 149. See Coxopodite and 

 Basipodite. 



Ferment-cells. In the epithelium of the liver-tubes in the 

 Gammarida? Max Weber distinguishes ferment-cells 

 and liver-cells. The former have in their plasma a 

 pellucid secretion in form of a large vesicle. The liver- 

 cells are full of little drops of secretion which are not 

 affected by water, though they are by ether. In the 

 opinion of P. Mayer, from whom these statements are 

 taken, one and the same cell in its passage in the liver- 

 tube from behind forwards probably performs different 

 functions, at one time secreting fat-drops, then differenti- 

 ating itself to a ferment-cell, after this being dispersed, 

 oi-, on being pressed further forwards, resuming the 

 production of fat (Die Caprelliden, pp. 150-156). 489. 

 Fibres musculaires, 1647. 



Filament (filum, a thread), a term sometimes applied to the 



antennary flagellum, sometimes to the so-called olfactory 



tubes or cylinders. 



Flagellum, also called terminal filament, fouet, funiculus, lash, 



seta, Geissel ; in the Amphipoda generally used only of 



the more or less whiplike series of joints attached to the 

 peduncle in the upper and lower antenna?. The shorter 

 lash ( ? the exopodite) often found on the inner side of 

 the upper antenna? is known as accessory seta, 105, 

 secondary or accessory flagellum, secondary appendage, 

 Nebengeissel, flagellum appendiculare. For a more 

 extended use of the word flagellum, see p. 153. 

 Flohkrebse, 170, 4S0. 

 Foot-jaws. See Maxillipeds. 

 Frontal organ, 477. 



Gammarus (/ta^jaapos, Ka/xapot, «a/*^upoj, cammarus, gammarus, 

 a kind of crab, lobster or shrimp, according to Martial 

 turning red when cooked), 5, 12, 40, 53, 1620. 

 Gancetto, a subchelate hand, 1622. 



Ganglion (yayyXia v, a tumour under the skin), a collection of 

 nerve-cells from which nerve-fibres are given off. For 

 the Caprellida? Mayer distinguishes a hind-brain with 

 the ganglionic knots in connection with it, namely, the 

 optic ganglion and the ganglia for the two pairs of 

 antenna? ; the subresophageal ganglion consisting of 

 several coalesced ganglia ; the supra-cesophageal ganglion 

 connected with- the frontal organ ; and a small unpaired 

 ganglion lying medio-dorsally, from wdiich runs an un- 

 paired nerve, probably to the constrictores pharyngis. 

 The ganglion of the first person-segment is in most 

 genera in contact with the subcesophageal ganglion, in 

 Proto actually coalesced with it. Each pera?on-segment, 

 from the second to the sixth, is provided with a 

 ganglion ; for the seventh segment and the rudimentary 

 abdomen there is a ganglion-complex, bearing traces of 

 the same arrangement as prevails in the Gammarida?. In 

 Gammarus ncglcctus G. O. Sars describes fourteen ganglia, 

 of which the three first belong to the head, the following 

 seven to the seven segments of the person, and the suc- 

 ceeding four to the pleon, three corresponding to the three 

 first pleon-segments, and the fourth and largest to the 

 three remaining segments, being itself probably com- 

 pounded of three originally distinct ganglia. The first or 

 cerebral ganglion is much larger than the rest. It has an 

 upper and a lower division. The lower, almost on a level 

 with the rest of the ganglionic chain, and situated at the 

 lower corner of the head, ends in four large conical pro- 

 cesses which supply nerves to the antenna?. The upper 

 division, placed vertically, much larger than the lower, 

 and of rounded square form, has above two obtusely 

 rounded lobes, separated by a median groove. Each of 

 these shoots forward a fine nerve, which ends in a little 

 ganglionic swelling at the root of the rudimentary 

 rostrum. From the hinder outer part of each lobe runs 

 the optic nerve. On the border of the two divisions of 

 the central ganglion are a pair of little rounded lateral 

 lobes. Two ganglia in close contact, separated from the 

 cerebral ganglion I?}' the oesophageal commissures, supply 

 nerves to the mouth-organs. For the Phronimida? Claus 

 states that the subcesophageal ganglion mass is derived 

 from the coalescence of six or seven ganglia, those of the 

 two first person-segments being included in the com- 

 plexus. The five following segments have each a ganglion, 

 but that of the seventh segment lies immediately under 

 its predecessor in the sixth segment instead of its own. 



