Miscellaneous. 239 



from the concentric moulding observable in the thickened corneous 

 operculum of the West Indian M. Marti, Poey. 



A redistribution of the species of Megalomastoma, grounded on 

 the construction of the operculum, is desirable. 



The specimens above referred to occur in my own collection. It 

 is probable that few cabinets besides that of Mr. H. Cuming possess 

 the materials requisite for the work. 



August 11, 1859. 



On two new species of American Ant-Thrushes. 

 By P. L. Sclater, F.R.S. 



1 . Myrmelastes plumbeus. 



c? . Nigricanti-plumbeus, alis caudaque obscure nigris ; tectricum 



alarium apicibus albo guttatis ; rostro et pedibus nigris. 

 ? . Mari similis, sed corpore toto subtus ferrugineo-rufo. 

 Long, tota 6"0, ahe 3*1, caudse 2*3, rostri a rictu LOo, tarsi I '2. 

 Hab. Upper Amazon, Rio Javarri [Bates). 

 Mus. Brit., P. L. S. 



The British Museum possesses both sexes of this fine, strong 

 Ant-thrush from collections lately transmitted by Mr. Bates from 

 Ega, but originating, I believe, from further up the stream. I have 

 a single male specimen from the same source. The female has so 

 nearly the same general appearance as Thamnophilus hyperythrus <$ , 

 that they might easily be confounded at first sight. 



2. Myrmelastes nigerrimus. 



Unicolor nigerrimus, tectricibus alarum superioribus, campterio 



proximis, alb is. 

 Long, tota 6 - 5, alee 3*3, caudee 2'3, tarsi 1'3. 

 Hab. Upper Amazon (Bates). 

 Mus. Brit. 



A single example of this bird occurred in the same collection as 

 the former species, and is now in the British Museum. It is quite 

 the same form as Myrmelastes plumbeus, with the exception of the 

 bill being slightly shorter and the feet rather stronger. It is marked 

 " Irides black, bill black." It is without doubt a male ; and it will 

 be interesting to see the female. — Proc. Zool. Soc. May 11, 1858. 



On the Habits of Aplysiopterus viridis. 

 By Dr. J. E. Gray, F.R.S. &c. 



This animal is not uncommon at this season (August) in Swanage 

 Bay. It is very peculiar in not having any distinctly marked foot, 

 except just a little in front of the narrow acute tip of the tail. When 

 walking on the surface of the vase in which it is contained, it only 

 touches the glass by this end of the tail and the front of the body 

 under the head and tentacles, the rest of the under surface of the 

 body being quite free, at some distance from the glass, and rounded, 



