()04 Mr. Y. E. Beddaid o/i some Points in 
the syrinx of Hierococojx just described. In Cuculus micro- 
pterus the rings which actually form the syrinx — i. e., the 
last tracheal and the few first bronchial semi-rings — are of 
the same red colour as are those of Hierococcyx, and they 
are also ossified as in that species. But the difference is, 
that instead of only three rings which must be relegated to 
the bronchial series there are four of these semi-rings. 
The pessulus has^ so to speak, moved a ring higher up ; 
the trachea has been a little more split than in Hierococcyx. 
The thin intrinsic muscles are, as before, attached to the 
last of the specialized bronchial semi-rings ; but in the present 
species that ring is naturally the fourth instead of the third. 
The pessulus is plainly seen, when the syrinx is viewed from 
behind, to bend upwards and to interfere between the other- 
wise closely approximated ends of the last tracheal ring. 
The split extremities of this ring do not meet except through 
the intervention of the end of the pessulus. There is no 
fusion between it and them. This state of affairs agrees 
exactly with my earlier description"^ of the syrinx of Cuculus 
canorus, to which I have already referred. 
Clearly related to the two genera which have just been 
mentioned is the much smaller Cuckoo referred to the genus 
Cacomantis, also of Old World range. In a specimen of 
this genus (I am quite uncertain as to the species) I have 
examined the syrinx, and find it to be exactly like that of 
Cuculus, and so far different from the syrinx of Hierococcyx. 
In Cacomantis, in fact, there are, as in Cuculus, four trachei- 
form bronchial semi-rings w^hich are ossified throughout. To 
the last of these are attached the slender mtrinsic syringeal 
muscles. I have already referred Cacomantis to the Cuculine 
section of the family on account of the muscle-formula of 
the thigh and the characters of the ventral pterylosis. This 
finishes what I have now to say respecting the anatomy of 
forms closely related to Cuculus. 
Before proceeding to add some new facts to our knowledge 
of the rather more remotely allied genus, Coccystes, I should 
Hke to point out certain features in which the group of 
* P. Z. S. 1885, p. 170. ■ 
