CRUSTACEANS 



estuary of the Thames, and from the same locality C. tenera, Brady ; 

 C. albomaculata, Baird, taken at Whitstable by Rupert Jones, at Girdler 

 Sand (Thames) and Margate by E. C. Davison ; C. gibbosa, Brady and 

 Robertson, found by those authors in the Thames Estuary ; C. tuberculata 

 (Sars) from Margatei; C. villosa (Sars), obtained by Davison at Margate 

 and Girdler Sand; C. navicula (Norman), of which Brady recognized 

 his Cythere Jidicula as a synonym, from the estuary of the Thames and 

 various other places, but in all of them rare, with a specific name 

 suggestive of the form, which Norman thus describes, 'ventral aspect 

 boat-shaped, the resemblance most striking ; centrally depressed at the 

 juncture of the valves; bow moderately sharp, of good breadth of beam, 

 sculptured with raised, threadlike concentric lines, representing the 

 timbers, while the small nodulous processes stand for the thole-pins. The 

 dorsal and end views bear out the illusion, the former representing a 

 boat viewed from below, with a well-marked keel, and the latter being 

 triangular, with gently rounded sides ; ' C.fuscata, Brady, found by Brady 

 and Robertson in the Thames,^ C. antiquata Baird from the Thames^ 

 and C whitei (Baird) from the Girdler Sand.* 



Cytheridea papulosa. Bosquet, has been found in the Thames 

 Estuary, by Davison, and of the same genus C. elongata, Brady, in Peg- 

 well Bay by Rupert Jones, and in shell sand from the Thames by Dr. 

 Brady ; C. torosa (Jones) has been found at Gravesend by Professor 

 Jones, at Girdler Sand by Davison, and in shell sand from Pegwell Bay 

 by Brady ; C. lacustris (Sars) was obtained from the Thames Estuary by 

 Brady and Robertson.* Eucythere declivis (Norman), of which E. argus 

 (Sars) is a synonym, is recorded from ' Girdler Sand,' this like most of 

 the specimens from that locality having been collected by Mr. E. C. 

 Davison. Loxoconcha impressa (Baird) ' in the shell sand from the 

 Girdler Sand' (Thames) ' is described as one of the commonest of British 

 species.' The generic name means ' oblique shell,' and in accord with 

 this Dr. Brady observes, ' the genus is well characterized by the oblique 

 " peach-stone " outline of the carapace.' To the same genus belong 

 L. guttata (Norman) from Girdler Sand, Thames, and ofFDungeness Bay; 

 L. viridis (O. F. Miiller), of which L. elliptica, Brady, from Girdler 

 Sand, is now recognized as a synonym ; and L. tamarindus (Jones) from 

 Margate and ' in shell sand, Girdler Sand.' Xestoleberis aurantia (Baird) 

 is reported by Brady and Norman from the estuary of the Thames and 

 from ofFDungeness Bay. This species shows 'colour deep brownish 

 orange, or sometimes white ; a very conspicuous black or deep crimson 

 spot in front of the eyes.' The genus. Dr. Brady says, 'is chiefly 

 distinguished by the peculiar form of the carapace, which is very low 

 and pointed in front, elevated and tumid behind, in these respects 

 offering a direct contrast to the genus Eucythere' It has the ' shell 

 very smooth and polished, ornamented with small round distinct 



» Brady and Norman, Transactions Roy. Dublin Society, ser. 2, iv. 143. 

 » Loc. cit. iv. 148. 3 Loc. cit. 168. ♦ Loc. cit. 169. 



• See Monograph of Post-tertiary Entomostraca, 179 (1874). 



I 237 33 



