g12.] R. B. SeymMouR-SEWELL : Surface-Living Copepoda. 315 
tion in the developmental changes that it is only in such cases 
as this, where a large number of stages can be obtained at the 
same time and place, that one is able with comparative ease to 
carry out investigations regarding the laws of development. The 
locality where the collection was made is situated at the mouth 
of the river close to the fairway buoy (‘“‘ Investigator’”’ station 
394, 16° 16’ 00” N., 96° 21’ 00” E., 13-xi-rgir), and hydrometer 
readings showed that the density of the water was very low, the 
average reading being 1002. 
In the following table I have given a list of the Copepoda 
(Gymnoplea) present in the two collections, and a comparison of 
the two faunas indicates that the collection from Chittagong 
was probably made further out to sea, where there was greater 
admixture of the estuarine and truly marine forms than in the 
Rangoon River estuary. 
RANGOON RIVER ESTUARY. 
Acartia spinicauda, Giesbrecht. 
Acartia tortantformis, sp. nov. 
Acrocalanus inermis, sp. nov. 
Centropages alcocki, sp. nov. 
OFF CHITTAGONG. 
Acartia spinicauda, Giesbrecht. 
Acartia tortaniformis, sp. nov. 
Acrocalanus gibber (Giesbrecht). 
Acrocalanus inernus, Sp. nov. 
Labidocera euchaeta, Giesbrecht. Canthocalanus pauper — (Gies- 
Paracalanus dubia, sp. nov. brecht). 
Pseudodiaptomus binghanu, sp. Candacia bradyi, Scott. 
nov. Centropages notoceras, Cleve,! 
(? = dorsispinatus, Scott and 
Thompson). 
Centropages furcatus (Dana). 
Centropages orsinit, Giesbrecht. 
Centropages tenuivemis, Thomp- 
son and Scott. 
Eucalanus monachus, 
brecht. 
Fuchaeta concinna, Dana. 
Labidocera acuta (Dana). 
Labidocera euchaeta, Giesbrecht. 
Labtdocera kréyert (G. Brady). 
Labidocera minuta, Giesbrecht. 
Paracalanus aculeaius, Gies- 
brecht. 
Paracalanus serratipes, sp. nov. 
Pontella andersont, sp. nov. 
Pontellopsis rvegalis (Dana). 
Undiniula vulgaris (Dana). 
Gies- 
1I am somewhat doubtful about these species. Cleve apparently considered 
them synonymous, but both accounts differ in certain details and a consideration 
of the matter will be found below, in the second paper dealing with the Copepoda 
from the Moscos region. 
