586 MR. A. H. GARROD ON THE [Nov. 3, 



tenuato ; apertura verticali, subovali, marginibus callo crasso 

 restricto junctis ; columella arcuata; labro sinuato, obtuso, intus 

 vix crenulato. 



Long. 6, diam. 9 mill. Apert. intus 6 mill, longa, 4 lata. 



Hab. Borneo. 



Poromya forbesi, H. Ad. (Plate LXIX. fig. 6.) 



P. testa transversa, subovali, ventricosa, tenui, albida, subpellucida, 

 radiatim exiliter punctata, epidermide tenui flavida scabra induta ; 

 umbonibus tumidis, eminentibus, submedianis : extremitate ante- 

 riori ovata ; extremitate posteriori oblique truncata, admarginem 

 dorsalem compressa ; margine ventrali arcuato. 

 Long. 20, alt. 14, lat. 9 mill. 



Hab. ? 



The genus Poromya of Forbes (=Embla of Loven) has been con- 

 sidered to be synonymous with Thetis of Sowerby and Eucharis of 

 Recluz. It should be kept separate from both, and they also be 

 recognized as distinct genera. Thetis, of which I am not aware of 

 there being any recent species, appears to belong to the family 

 Veneridse, while the others are members of Corbulidse. 



P.S. — Since writing the above I find that a specimen of Neritopsis 

 radula, with its operculum, has been received by Dr. Souverbie from 

 Ouagap, one of the Caroline Islands, and that the operculum has 

 been described by him in the April Number of the ' Journal de Con- 

 chyliologie.' 



EXPLANATION OF PLATE LXIX. 



Fig. 1, la. Apicalia holdsworthi, p. 585. 



2. Tudicla spirilla, p. 585. 



3. Barclayia inceria, p. 585. 



4. 4a, 4b. Operculum of Neritopsis radula, p. 585. 



5. 5 a. Paludomus lutens, p. 585. 



6. Poromya forbesi, p. 586. 



6. On some Points in the Anatomy of the Parrots which hear 

 on the Classification of the Suborder. By A. H. Garrod, 

 B.A., F.Z.S., Fellow of St. John's College, Cambridge, 

 Prosector to the Society. 



[Received September 15, 1874.] 

 (Plates LXX. & LXXI.) 



In a former communication*, a review of certain of the most 

 variable characters found amongst the Columbce enabled me to give 

 hints with regard to the mutual relationships of the different genera 

 of that considerable family, which I hope will be found of service. 

 On the present occasion it is my desire to follow out a similar method, 

 taking the Psittaci, a suborder quite as, and perhaps even more, 

 difficult to arrange by external features only. 



* P. Z. S. 1874. p. 249. 



