'258 CEYLON PEARL OYSTER REPORT. 



Euterpina acutifrons (Dana). 



Well distributed throughout the traverse, occurring at 48 stations, from the 

 Mediterranean to Ceylon. 



Tachidius littoralis, Poppe. 

 One specimen was taken in the Gulf of Suez. 



Clytemnestra scutellata, Dana. 



Occurred at 1.0 Indian Ocean stations, and 3 round Ceylon, viz., off Pantura to 

 the south of Colombo, at Cheval Paar and west of Periya Paar, Gulf of Manaar. 



Clytemnestra rostrata (Brady). 



Found at 8 stations, from the Mediterranean, Gulf of Suez. Pied Sea, and tin- 

 Indian Ocean, and once at Ceylon, near the Muttuvaratu Paar. 



Tegastes sphserica (Claus). 

 One specimen of this littoral species was taken between Port Said and Suez. 



Tegastes nigrans (T. and A. Scott). 

 A number of specimens were found in washings from Muttuvaratu pearl oysters. 



Tegastes imthurni, n. sp. — Plate IV., figs. 1 to 9. 



Length, female 0'6 millim. to 0'45 millim. ; male unknown. 



Cephalothorax composed of 6 segments ; the first broadly falciform, and extending 

 ventrally to double the width of the other segments. 



Abdomen 4-jointed, the first extending ventrally into a long projection, truncated 

 at end. A large rounded hook from the centre of the 1st segment projects over the 

 posterior ends of the other segments. 



Anterior antenna? 6-iointed, the relative lengths beinp- : — ' 



J s & 25. 18. 9. 4. 4. 4. 



Posterior antennre and mouth organs, with the exception of the 2nd rnaxillhpeds, 

 as in T. sphcerica. In this species the inner concave edge of the chelate hand, instead 

 of being pectinated, has a small funnel-shaped expansion, the upper circular edge 

 being clothed with fine hairs. The inner projecting corner of the hand has, on the 

 upper edge, about 10 short spines arranged in a pectinate manner. 



The 1st pair of natatory legs are similar to T. sphcerica. The 2nd, 3rd, and 

 4th pairs differ considerably from that species, however, and also from the generic 

 description in Brady's Monograph of British Copepoda. In the 2nd and 3rd pairs of 

 T. imthurni, and also in T. donnani, and in T. twynami, the inner branches are 

 composed of 3 joints, while the outer branches have only 2 joints. The 4th pair has 

 the outer branch 3-jointed, and has only 2 joints in the inner branch. The basal 

 joint of the inner branch of this pair is a wide foliaceous expansion with thickened 



