Yol. 54.] THE DECAPOD CRUSTACEA OP ENGLAND. 27 



triangular telson. Chelae strong, very unequal in size; meropodite 

 robust, expanding rapidly towards the distal end, which is nearly as 

 wide as the joint is long, is circumscribed by a distinct sulcus, and 

 has the upper border prolonged into a stout spine ; hand as long 

 as the carapace is wide, and a third longer than wide, oval in 

 section ; dorsum smooth. Fingers nearly as long as the hand, 

 prehensile borders with several blunt teeth. Posterior pairs of 

 limbs slender, and nearly equal in size. Bell and Milne-Edwards 

 describe the orbits as being without marginal fissures ; but a 

 specimen in the Woodwardian and another in the British Museum 

 (Is'o. 59218) show distinctly the characters which I have described ; 

 probably these notches become obliterated by age. 



RemarTcs. — In 1865 Milne-Edwards figured and described a 

 species from the London Clay of Sheppey, which he named 

 Necrozius Boiverhankii. In 1867 Dr. Woodward discovered a speci- 

 men in the British Museum (No. 59400), from the London Clay 

 of Holloway, which he recognized as the form described by Milne- 

 Edwards ; and he afterwards published an excellent description 

 and an enlarged figure of it in the ' Geological Magazine,' with 

 remarks on its generic alliance. Subsequent examination of this 

 and other specimens, however, has convinced me that the species 

 described by Milne-Edwards is identical with that previously 

 determined by Bell and named Cydocorystes pulcJiellus. 



Distribution. — The specimen figured by Bell is in the British 

 Museum (No. 59101), as also four others from the London Clay of 

 Sheppey ; also a carapace from ' Copenhagen House ' which is 

 29 mm. wide. A. nearly perfect example from the London Clay of 

 Clacton is in the Woodwardian Museum. Specimens from the 

 Crag (derived from the London Clay) are in the Woodwardian and 

 Ipswich Museums. 



Genus Neceocaecinits, Bell. 



Necrocaecinus Becblei (Deslongchamps). (PI. I, fig. 9.) 

 1863. Bell, Monogr. pt. ii, p. 20 & pi. iv, figs. 4-8. 



Supplementary. — The armature of the antero-lateral border of 

 the carapace is irregularly expressed ; small tubercles not un- 

 frequently occur on the postero-lateral border. The dorsum bears 

 16 or 18 areolar tubercles, those on the lateral gastric and the 

 hepatic lobes forming an undulating row (in N. Woodivardii these 

 tubercles are arranged in a straight line). The normal interruption 

 of the cervical sulcus, and the minute puncta between the meso- and 

 urogastric lobes, indicating the attachment of gastric muscles, are 

 well marked in this species. Orbits approximate, oval, widely open 

 inwardly, directed obliquely upward ; two notches in the upper and 

 one in the lower margin. Endopodite of external maxillipeds 

 slightly wider than the exopodite. The abdomen, which is seldom 

 preserved, is seven-jointed ; in the first 5 segments the mesonotum 

 is raised into a sharp transverse rib ; the penultimate segment is 

 twice as long as that preceding it. The abdomen of the female is 



