180 Transactions of the South African Philosophical Society. 



antennas (fig. 13) are composed of three segments and have two, 

 perhaps three, terminal claws. 



The mouth-cone (fig. 12) with the mandibles (mcl) and the 

 maxillary prominences (mx") are exactly as in the female, except 

 that the last-named structures seem to have no terminal setae. 



The first four pairs of feet (figs. 15-17) have the protopodite 

 indistinctly divided into two segments, the distal one bearing, in the 

 first three pairs, a seta on its outer edge. The rami of the first four 

 pairs are each composed of three segments. The distribution of 

 their setae is shown by the following table, drawn up after the plan 

 followed by Dr. Giesbrecht : — 





Rel. 



Re 2. 



Re 3. 



Ril. 



Ri2. 



Ri3. 



1st Foot... 

 2nd Foot 

 3rd Foot... 

 4th Foot... 



ISe OSi 



ISe OSi 



ISe OSi 









 ISe ISi 

 ISe ISi 

 ISe OSi 



2Se ISt 3Si 



2Se ISt 4Si 

 2Se ISt 5Si 

 2Se ISt 5Si 















OSe ISi 



OSe ISi 

 OSe 2Si 

 OSe 2Si 

 OSe 2Si 



ISe 3Si 

 ISe 4Si 

 ISe 5Si 

 ISe 4Si 



The feet of the fifth pair (fig. 14, p : >) consist each of two small 

 papillae, of which the inner is the larger, each bearing a single seta. 



Younger Stages. 



Specimens of younger stages were occasionally found, but on 

 account of the very indistinct segmentation of the body and limbs 

 it was not possible to refer them to the various larval stages 

 recognised in the Copepoda. The youngest stage observed is repre- 

 sented on Plate XVIII. , fig. 9. The total length is about -36 mm. 

 The fourth pair of feet are present as bilobed prominences, and the 

 abdomen is divided into two segments. The first three pairs of feet 

 (fig. 10) have both rami in the form of ovate leaflets, the exopodite 

 with four spiniform points on its distal margin ; the second of these 

 points, from the outer side, is larger than the others, and probably 

 represents the single curved claw of the adult female. 



Mode of Occurrence and Probable Life-history. 



All the specimens were found in the stomach of adult zooids ,or 

 nearly full-grown buds. The degree of infection varies in different 

 colonies, or perhaps in different branches of the same colony. In 

 some of the pieces of Ccphalodiscus-coloiiy which I examined nearly 

 every adult zooid contained one or more parasites, but in other 

 pieces they were much less abundant. The position generally 

 occupied by the parasite in the stomach of its host is shown in 



