llic lillihs 



Studies oil iiiariiip Ostracods I'j! 



a closer study of the morphology of these animals and the main features of this became rather 

 well known comparatively soon. 



At first rather serious mistakes were made in interpreting the limbs, the organs which, 'i'ii'''in<:ifin-uiu<inoj 

 after the shell, quite naturally aroused the greatest attention; this is, of course not so surprising 

 when one remembers the frequently peculiar type of these organs, how closely together they 

 are situated and the small size of the forms investigated. 



Thus H. Milne Edwards in his work of 1840 denotes these organs as follows: „antenne 

 superieure j^ediforme" (= first antenna), ,,patte natatoire" (= second antenna), ,,antenn(' 

 inferieure" (= mandible), ,,mandibule" (this organ is interpreted by C. Claus, 1873, p. 214 as 

 ,,einen paarigen Seitenfortsatz der Oberlippe"; it seems to me impossible to decide with certainty 

 whether this assumption is correct or whether the organ described by MiLNE EDWARDS may 

 possibly be the maxilla), ,,machoire de la premiere paire" (=fifth limb), ,,machoiredeladeuxieme 

 paire" (presumably the sixth limb; it seems to me rather improbable that it should be tlie 

 maxilla; if it were so the sixth limb, which is rather conspicuous, would not have been observed 

 at all) and „patte ovifere" (= seventh limb). The descriptions and drawings of these organs 

 are extremely incomplete and uncertain. This author writes on p. 41U: ,,Les deux paires 

 d'antennes .... constituent des rames natatoires ..." — In W. Baird's work of 1847 

 we find the following interpretation: ,, anterior antenna" {— the mandible), „natatory foot" 

 {— the second antenna), ,, second pair of antennae" (= the maxilla), ,,the mandible I did not 

 succeed in seeing'", ,, first pair of jaws" (= the fifth limb), the sixth limb is not mentioned, tiie 

 ,,oviferous foot" (^ the seventh limb). Compared with this interpretation the one we find 

 in the same author's work of 1850 a may be considered as an advance, even though 

 a small one: „first pair of antennae" (= first antenna), „second pair of antennae" (=^ man- 

 dible), , .natatory foot" (= second antenna), ,,the mandible is a flat plate armed at its extremity 

 with three or four sharp teeth", p. 177, (it is difficult to decide which limb or part of a 

 limb is referred to; it may possibly be a part of the fifth limb), „the fii'st pair of jaws is 

 composed of a large body with three or four appendages, like fingers, armed with stout cilia, 

 and having attached to each a large branchial plate", p. 177 (here too it is difficult to decide 

 which parts are referred to, possibly the sixth limb with the vibratory plate of the fifth; it 

 seems improbable that it should be merely parts of the fifth limb that are referred to, one reason 

 among others being that it is certainly a species belonging to the genus Philomedes that has 

 ftn-med the basis for these statements), „second pair of jaws" (^ maxilla), and ,,oviferous foot" 

 (seventh limb) — S. FISCHER may be said to have been still more unfortunate in his work of 1855 : 

 „erste Antenne" (^ first antenna), ,,zweite Antenne" (= mandible), „Maudiber' (=- the fiftii 

 limb or the masticatory part of the fifth limb + the sixth limb), „Maxille" (=^ maxilla), 

 „hinter ihm" (maxilla) „liegt die ziemlich groBe und starke Kieme" (either the vibratory plate 

 of the fifth limb or the sixth limb) ,,und unmittelbar unter derselben zwei uach riickwarts 

 gerichtete, mit starken befiederten Borsten versehene Palpen" (-- the seventh limb?). This 

 writer is especially unfortunate in the interpretation of the second antenna; the exopodite 

 of this limb is interpreted as the „erste FuB", its endopodite as ,,zweiter FuB". Fischer also 

 surpasses the two first-named writers in the incompleteness and uncertainty of the descriptions 



