476 Petri III. — Twentieth Annual Report 



The caudal lamina of the male appears to have only five spines on both 

 sides (fig. 32), no trace of a sixth could be observed. 



The male described and figured here does not agree with Nematohamma 

 obliqua, Brady and Norman, the structure of the antennse and of the 

 secondary branches of the antennules differs considerably from that of the 

 same appendages in N. obliqua. 



No male of Sarsiella capsula appears to have been described hitherto. 



Conchcecea elegans, G. 0. Sars. PI. xxv., fig. 33. 



A specimen of this species was dredged ISO miles north-east from 

 Buchan-ness (about sixty miles to the east of the Shetland Islands) on 

 May 22nd, 1901. Another specimen was obtained in the stomach of a 

 whiting captured in 65 fathoms about 10 miles off Aberdeen on the 19th 

 of the same month. 



Order BRANCHIOPODA. 



POLYPHEMED^. 



Genus Podon. 



Three species of Podon have been described from the North Sea viz. 

 Podon polyphemoides, Leuckart, Podon leuckartii, G. 0. Sars, and Podon 

 intermedins, Lilljeborg, and two of these — the first and the third — have 

 sometimes been included in lists of British Crustacea ; there is a proba- 

 bility, however, that Podon leuckartii has sometimes been mistaken for 

 P. polyphemoides, and as I have, with the assistance of Professor Liilje- 

 borg's great work on Swedish Cladocera recently published, been enabled to 

 recognise Podon leuckartii in some tow-net gatherings from the Firth of 

 Forth and also from the Moray Firth, I will here indicate what seem to 

 be the more obvious differences between this species and Podon inter- 

 medins, which is occasionally observed in the Firth of Clyde, and 

 between both of these and Podon polyphemoides. 



Podon leuckartii (G. O. Sars). PI. XXV., figs. 23, 24. 



The specimen represented by the drawing measures about a millimetre 

 in length. The lower branches of the antennae are composed of three, the 

 upper of four joints as in the other two species referred to above ; the 

 joints of the lower branches are sub-equal in length, and the first two bear 

 each one and the last four terminal setae, the first joint of the upper 

 branches is very small, but other three are larger and sub-equal in length, 

 and are provided with the same number of setae as the lower branches 

 (%. 24). 



The caudal spines are strong and slightly curved, and are rather longer 

 than the caudal spines of Podon intermedins. 



Habitat. — Firth of Forth and the Moray Firth. 



The species does not appear to be rare on the east of Scotland : it has 

 probably been mistaken for Podon polyphemoides. 



Podon intermedins, Lilljeborg. PI. XXV., figs. 25, 26. 



1853. Podon intermedins, Lilljeborg, De Crust, ex ordinibus 

 tribus': Cladocera, Ostrocoda, Copepoda, in Scania occurr., sec. 

 ii. ; da Crust. Marina, Ord. Clad., p. 161. 



The specimen represented by the drawing measures about 1 *5 mm. The 

 antennae (second antennae) are somewhat similar in structure to those 



