506 PROFESSOR E. RAY LANKESTER,. 
15. GeGENBAUR, Carl. ‘Elements of Comparative Anatomy,’ English 
translation, 1878, p. 230. 
16. Huxtey, Thos. H. ‘The Anatomy of Invertebrated Animals,’ 
1877, p. 260 and p. 374. 
17. Harcxen, Ernst. ‘Generelle Morphologie,’ vol. ii, p. xe. 
18. Owen, Richard, ‘ Lectures on Invertebrate Animals,’ 1843, p. 181. 
19. Straus DurKHEIM in Appendix to the sixth volume of the French 
translation of Meckel’s ‘Comparative Anatomy,’ 1829. 
Embryology of Arachnida. 
20. Batrour, F. M. ‘ Notes on the Development of the Araneina,” 
‘Quart. Journ. of Micr. Science,’ vol. xx, 1880. 
21. Merscuntkorr, Elias. ‘“ Embryologie des Scorpions,” ‘ Zeitschrift 
fiir Wiss. Zoologie,’ Bd. xxi, 1870. 
As I am about to endorse the conclusion arrived at by an © 
eminent naturalist of the first half of this century, viz. 
Straus Durkheim, it will be well to give here at once the 
grounds upon which he based that conclusion. 
Straus Durkheim maintained that Limulus should be 
classified with the Arachnida, but the publication \of his 
views on the subject appears never to have taken a very 
definite or satisfactory form. In fact the only record of 
Straus Durkheim’s teaching on this subject which I can 
find is in the French translation of Meckel’s ‘General 
Treatise on Comparative Anatomy.” MM. Riester and 
Alph. Sanson carried out this translation, and added many 
notes in the form of appendices to each volume. At the 
end (p. 497) of the sixth volume, which bears the date 
1829-1830, there is a note headed, “Sur l’appareil locomo- 
teur passif des Arachnides,” which appears to be an abstract 
of a memoir ‘On the Comparative Anatomy of the Arach- 
nida, read to the Academy of Sciences, June Ist, 1829, but 
never, I believe, published. M. Straus Durkheim com- 
municated its contents to MM. Riester and Sanson. From 
this note I submit a few extracts. The authors commence, 
“La classe des Arachnides, dans laquelle M. Straus com- 
prend le genre Limule, formant a lui-seul un ordre designé 
sous le nom de GNATHOPODES, et dont il isole les Pycno- 
GONIDES qu’il renvoie aux Crustacés, offre dans la disposi- 
tion de son squelette et des muscles qui en meuvent les 
diverses piéces, des particularités tellement tranchées qu’on 
ne peut y méconnaitre un type different. C’est de ce 
squelette que sont tirés les traits principaux propres a 
characteriser la classe des arachnides en general, et qui 
consiste dans la disposition des pattes rayonnant sur un 
sternum commun, dans la présence @un sternum cartia- 
gineux intérieur, dans Pabsence d’antennes.” 
