102 ARNOLD W. COOPER. 



species witli Diaptomus oi- Paradiaptomus, and accordingly a 

 new genus (Adiaptomus) has been made for its reception. 



The descriptions of Diaptomus and Paradiaptomus have 

 been taken from the Das Tierreich, Copepoda, Gymnoplea, 

 by W. Giesbrecht and D. Schmeil. 



I am also indebted to Dr. Ernest Warren (Director of the 

 Museum) for much valuable assistance with regard to this 

 paper. 



EXPLANATION OF PLATE XII, 



Illustrating Mr. Arnold W. Cooper's " Notes on a New 

 Species of Gymnoplea from Richmond. Natal, South 

 Africa; Adiaptomus natalensis (gen. et sp. no v.)." 



Fig. 1. — X 30. Side view of female of Adiaptomus natalensis. 



Fig. 2. — x 40. Abdomen, male, side view : note the rounded pos- 

 terior edge of the last thoracic segment. 



Fig. 3. — x 40. Abdomen, female, veutral^-iew; note the backwardly 

 directed flange of last thoracic segment. 



Fig. 4. — x 40. Antenna 1, male. Right, twenty-three joints ; twen- 

 tieth joint doiiljle -hinged, fifteenth to nineteenth swollen. Left, twent}^- 

 six joints like Fig. 4. 



Fig. 5. — x 40. Antenna 1, female ; twenty-six joints, the additional 

 joint apparently due to the division of the second joint of typical limb. 

 The si^ine (s.„), which is usually in the middle of the second joint, is 

 found at the proximal end of the third joint. 



Fig. 5a. — x 40. Proximal joints of antenna 1, female of Diap- 

 tomus orientalis. to show position of spine s.g on second joint, and 

 to compare with the position of spine s.^ in Fig. 5. 



Fig. 6.— x 80. Antenna 2. male. 



Fig. 6 a . — Face view of terminal joint of endopodite. 



Fig. 7. — X 80. Manditile. right; exoj^odite, one joint, not separable 

 from basipodite. 



Fig. 8.— X SO. Maxilla 1. left: note the two outer lobes as in 

 Diaptomus. 



