66 Dr. A. Voeltzkow on the Oviposition and 
Crinoid morphology to regard their resemblances as due to 
homogeny rather than to homoplasy. 
Imperforate Articulation. 
Reference to “ British Fossil Crinoids,” II. p. 314, will 
show that there is some difficulty in distinguishing between 
those forms of joint that are there called “ Loose suture ”’ 
and “ Muscular articulation.” There are among Inadunate 
Crinoids many instances of arm-joints in which there is a 
well-defined fuleral ridge, combined with muscular and liga- 
mental depressions, but in which the axial canal does not 
happen to be separated from the ventral groove by stereom 
and so does not perforate the fulcral ridge. It might be 
advisable to distinguish these joints as ‘ Imperforate articu- 
lation,” and to call the muscular articulation in which “ the 
articular ridge, whether vertical or transverse, is always 
perforate,” ‘‘ Perforate articulation.” 
It is unfortunately necessary to explain that the word 
“joint” is used here and throughout my papers in its ordinary 
English and anatomical sense, and not in that restricted and 
different sense which is usually ascribed to it by crinoidolo- 
gists and cooks. 
VIUII.— On the Oviposition and Embryonic Development of 
the Crocodile. By Dr. A. VoEurzkow, of Majunga, 
Madagascar *, 
THE Madagascar Crocodile, Crocodilus niloticus, Laur. (mada- 
gascarvensis, Grandid.), is not only one of the commonest 
reptiles, but perhaps the commonest Vertebrate of the island. 
It is found in large numbers wherever there is water, in every 
pool and stream. The natives distinguish two species, one 
(Cr. niloticus) with a longer, and another with a shorter head 
and greater length of body ; the latter is said to occur only 
in the large rivers in the primeval forest, and the natives are 
extraordinarily afraid of it, as it is stated to be very savage ; 
it is probably identical with Cr. robustus, Vaill., Grandid. I 
* Translated from the ‘Mathematische und Naturwissenschaftliche 
Mittheilungen aus den Sitzungsberichten der Ké6niglich Preussischen 
Akademie der Wissenschaften zu Berlin,’ Heft ii., 1891, pp. [115] 51-56 
[120]. 
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