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



ike form of the flagellum of the maxillipeds of the crabs, and serves to retain the eggs in 

 the thorax of the mother," p. 49. 

 The Crustacean mouth-opening is described, p. 61, as bounded in front by a small horny or bony 

 plate called the labrum or upper lip, and behind by a plate, generally bifid, called the 

 tongue, laiiguette, but which " might better be called the lower lip." The sides of the mouth 

 are occupied by the mandibles, " which often carry an articulated appendage, that has been 

 called the mandibular palp, but which appears to be the continuation of the stem of the 

 limb, and not the analogue of the part above-called the palp." After treating of the 

 maxillfe and maxillipeds, he comes to the Oanal digestif, which runs from the mouth to the 

 anus, which is always in the terminal segment. This canal is composed of three parts, the 

 oesophagus, stomach and intestine. In the Edriopthalma he observes that the stomach is 

 constructed on essentially the same lines as in the Podophthalma. He notes, p. 72, that in 

 Orchestia " there exist in the anterior part of the stomach, near its oesophageal opening, 

 two little ciliated teeth." These are the structures for which in this Report the expression 

 triturating organs has been adopted. On page 80 he remarks that "in the Amphipoda 

 and Lsemodipoda it is the llageUa {les fouets) of the thoracic limbs that appear specially 

 _ I assigned to the exercise of the respiratory functions ; these organs, from eight to twelve in 

 number, take the form of large membranous vesicles suspended below the thorax between 

 the ambulatory feet, and a current of water set in motion by the natatory feet of the 

 abdomen continually bathes them." 

 In describing the antennse of Crustacea, p. Ill, he says that the tige or stem is composed in 

 general of a stouter part called the peduncle, with on«, two, or three joints, and a more or 

 less elongate terminal portion, many-jointed, which he calls " tige ferminale." The " palp " 

 takes the form either of a second terminal multiarticulate lash, fixed at the extremity of the 

 peduncle, or of a large horny plate inserted at the base of the antenna, whUe the remaining 

 accessory portion, when present, also constitutes a terminal lash {iin filet terminal). 

 He notices, p. 113, that the Crustacea known under "le nom de Talitres ou de Puces de mer " 

 must have the sense of smell, as they gather round decaying food after it has been buried. 

 On p. 116 he gives the following account of the eyes as examined in " Amjjhitoe Prevostii" 

 and a few other Edriophthalma; "chez ces animaux on trouve d'abord pour chaque ceil 

 compost une cornea Usse sans division; mais imm^diatement derrifere cette lame t^gumentaire 

 il existe une secoude tunique, de meme nature et egalement transparente, qui y adhfere 

 intimement, et qui est divisde en une multitude de facettes hexagonales ; derriere chacune 

 de ces facettes ou corn^ules est situ6, comme d'ordinaire, un cristallin dont la face anterieure 

 est convexe et dont la face posterieure, qui se prolonge en nn cone a sommet obtus, est 

 contigue a un petit cylindre gelatineux, avec lequel le filet correspondant du nerf ojjtique se 

 confond." On p. 121 he says that in Gyarims there are two smooth eyes and two compound 

 facetted eyes, as to which see Note on Savigny, 1816. He repeats the account of the nerve- 

 system of Talitrus from a paper by Audouin and himself road in 1828, and at page 147 he 

 says that, combining Eathke's observations with theirs, " on peut conclnre que le systeme 

 nerveux des Crustaces se compose toujours de noyaux medullaires dont le nombre nonnal est 

 egal a celui des membres, et que toutes les modifications qu'on y rencontre, soit a diveises 

 epoques de I'incuhation, soit dans differentes esphces de la serie, dependent principalement des 

 rapproehemens plus ou mains complets de ces noyaux, agglomeration qui s'opih'e des cotes vers 

 la ligne mediane, en meme temps que dans la direction longitudinale ; mais peuvent tenir 

 aussi en partie a un arret de developipement dans im certain nombre de ces noyaux." 

 In the chapter on development it is remarked, page 199, that among the Edriophthalma the head 

 is much larger [proportionally] in the young than in the adults, that the abdomen often 

 shows analogous differences, and that when in the adult one of the pairs of feet exhibits 

 some peculiarity of structure, the anomaly is either not found, or is little apparent, in the 



