CRUSTACEANS 



the second antennae, Mr. Hodgson in his Synopsis speaks of the dorsal 

 or external branch as the posterior, the ventral or inner as the ante- 

 rior, while Dr. Baird does just the reverse. Specimens of Cladocera 

 are usually figured with the head uppermost. When the antennae are 

 erected the ventral branch faces forward, when they are depressed the 

 dorsal one occupies this position. It is therefore inconvenient to dis- 

 tinguish them by terms which have no fixity of application. Professor 

 Lilljeborg distinguishes B. longirostris as having the spines of the caudal 

 ungues in the female divided into two series, while in the other species 

 of the genus the series is single. 



In the family Macrotrichida? Warwickshire lays claim to Ilyocryptus 

 sordidus, Lievin, and Drepanotbrix dentata, Euren. Already in 1881, 

 Mr. H. E. Forrest, F.R.M.S., had recorded the former as obtained 

 ' probably from a small pond in Sutton Park near Birmingham.' 1 Mr. 

 Hodgson gives its distribution as ' common : Kingswood, Olton Canal, 

 Sutton.' The generic name alludes to its habit of hiding in the mud, 

 and the specific name enforces the moral that mudlarks will still be 

 muddy. The terminal claws in this genus are very long and the intestine 

 straight, subapically dilated, whereas in Drepanotbrix the terminal claws 

 are small and the intestine forms a large loop. The name of the latter 

 genus signifies sickle-haired or sabre-haired, and alludes to a rather 

 minute character. In the second antennas the inner branch has on 

 its first joint a long seta or hair, which is slightly curved like a sabre, 

 and without any articulation in the middle such as is found in the 

 seta of the second joint. In framing generic characters for the 

 Cladocera a census has been taken of the hairs on the second antenna?. 

 Hence unwonted attention has been drawn to parts that might otherwise 

 be thought rather insignificant. The specific name dentata alludes to the 

 dorsal tooth or stout spine on the subcircular carapace. 



Of the fourth family, often called Lynceidae but more correctly 

 Chydoridae, there are ten species assigned to Warwickshire : Chydorus 

 spbtzricus (O. F. M.), 'abundant, clear water'; C. g/o&osus, Baird, ' not 

 uncommon ' ; Eurycercus lamellatus (O. F. M.), ' abundant in clear weedy 

 pools and canals ' ; Acroperus harpa \harpcz\, Baird, ' generally distributed, 

 clear water ' ; ' Lynceus quadrangularis, canal, Olton ' ; Graptoleberis 

 testudinaria, Fischer, ' Olton Reservoir ' ; Alonella nana (Baird) , ' common : 

 Kingswood, Olton, Barnt Green ' ; Peracantha truncata (O. F. M.), 

 'canal, Olton; Alvechurch ' ; Pleuroxus trigonellus (O. F. M.), ' Alve- 

 church ' ; P. uncinatus, Baird, ' canal, Olton ; Windley Pool, Sutton.' 



In regard to Lynceus quadrangularis, O. F. M., it needs to be 

 explained that the genus Lynceus was established by O. F. M tiller, one of 

 the chief pioneers in entomostracan science. But, as so often happens 

 when new paths are opened up in zoology, this early genus was far too 

 comprehensive for subsequent requirements. It had to be much 

 restricted, and is now properly confined to the Phyllopoda. The 

 Cladocera once included in it are distributed under various other generic 



1 Midland Naturalist, iv. I . pi. I . 

 181 



