I»Y< DA 



l.i: ■■ uda; Latreille: le dernier segment du corps; Lamarck: 



domen; Johnston: abdomen; Milne-Edvards: abdomen; 

 Hinterleib; Kroyer: Bagkrop, abdomen; Wilson: abdomen; Dohrn: Hinterleib; 

 hi: Abdomen; II . ■ i k : abdomen; Adlerz: abdomen; Hansen: Bagkrop (abdomen); Sars: Hale- 

 ntum caudale). 

 The appellation of thi^ part of the trunk was in the early authors (L i n n e and O. Fabricius) 

 simph cauda, tail; but Latreille having pointed out that it was a part, a segment, of the trunk 

 If, the first name was displaced liy the appellation abdomen and the translations of it (Hinterleib, 

 krop), which was adopted by all authors until Sars, the opinion being, I suppose, that it corre- 

 the abdomen of tla- other Arthropoda, especially that of the [nsects and the Arachnida. 

 wire, bas meant to adopt the "Id name of tail, hut on account of the prevalent aversion 

 this appellation, lie has altered it to the mediate one of caudal segment, and I have followed him 

 partly ol similar reasons. As to its development the caudal segment is the hindmost part of the 

 hindmost principal division of the embryo, and until a far advanced stage in the larval development 

 it forms a hindmost, gradually more protruding, process of tin- fourth segment of trunk. If upon the 

 whole it is separated from this segment by a dermal suture, this does not take place until the third 

 larval stage. It never hears limbs, hut the intestinal canal opens in the end of it with a weak squir- 

 ting apparatus. Thus the caudal segment no doubt belongs to and makes the hindmost 

 [■art or segment of the same principal portion to which the four preceding segments 

 belongs; it is no separate part of the body, different from the foregoing segments of the trunk, no 

 abdomen in contradistinction to a thoracical part, lying before it. The caudal segment can be pro- 

 portionally very long, almost as long as the body, and then it is also well separated from the fourth 

 lent of thf trunk and very slender; there is no trace of division in joints, not even in Zetes 

 [/in- is has been maintained. On tin- other hand this segment may also be quite small, as it 



were, rudimentary, as I know from ,i not described genus among the collections, which the Smithsonian 

 Institute has given me for examination. 



Lateral process of the body for the insertion of the ambulatory leys [processus 

 lateralis), fiy. i pel. 



Sars: Legemets Sidefortsatser (processus laterales corporis) til Faeste tor Gangfodderne. 

 Thi 5Ses of the body and the ambulator) legs attached to them, are structures charac- 



oida, as they are not formed by germinating or growth of a particular cellular 

 ip but, as is distinctly seen from my drawings of the embryo, by a bag-like constriction of the 

 m, in the same manner as the embryonal limbs (the chelifori and embryonal legs). They are 

 in • i of the body, and so it will easil) be understood, that the intestinal canal and 



:ii continue far into the ambulator) legs as processes of tin body. 

 C helifi i. Kg, i , /// and i <i. 



one: palpi; 0. Fabricius: palpi; Latreille: mandibules; later (Regn. an. ed. II) : antenne- 



ch: mandibular; Savigny: pei cundi; Lamarck: antennules; Johnston: mandib- 



Milne-Ed pattes-machoires ; Erichson: erstes Kieferpaar or Scherenkiefer (Mandibeln); 



(antennae cheliformes) ; later Kindbakker (mandibular); I'.ohm: Kieferfuhler; Wilson: 



