134 CRUSTACEA. 



pair of legs closely scabroso- punctate ; chelae oval, very slender, 

 about double the length of the carapace, not very unequal, 

 greatest width about half the length from the base of the little 

 finger to the carpus ; section subrhomboidal, outer angle ob- 

 tusely carinated, smooth, sides obtusely rounded in the mid- 

 dle, inner edge with two rows of about four large spiniform 

 tubercles arched forwards ; fingers about one-third longer than 

 the base, equal, subcompressed, rounded, straight and of nearly 

 equal width throughout, nearly smooth, with a raised line of 

 very minute teeth on the inner edge ; carpus small, section 

 oval, scarce half the length from its tip to the base of the 

 moveable finger, finely punctured, and with a few strong 

 spines ; arm compressed ; the other legs slender and nearly 

 smooth (third and fourth pair 1 line in diameter). 

 This species is much more common in the London clay than 

 the H. gammaroides (M'Coy), which it resembles, although only 

 half the length ; it may be distinguished therefrom by the finer 

 and more uniform granulation of the sides, the greater length of 

 the nuchal furrow, and its being placed farther back towards the 

 posterior margin ; the cheeks, instead of being strongly carinated 

 and spined, are only obtusely rounded and nodulated; the 

 chelae are more slender, and the segments of the abdomen differ 

 in the present species, having the anterior smooth portion of each 

 more convex and separated by a much deeper furrow from the 

 posterior part, which in the H. gammaroides is closely punctate 

 in the first segment only, the others being polished with compa- 

 ratively slight distant puncta, while in the H. Belli the hinder 

 parts of all the segments are equally rough with a coarse close- 

 set punctuation. 



I dedicate this species to Prof. Bell, from whose able pen we 

 may one day expect an illustrated volume on all the Crustacea of 

 the London clay, for which I believe the most ample materials 

 exist in metropolitan collections which will be at his disposal. 

 Mr. Morris, in the preface to his Catalogue, mentions in the ca- 

 binet of Mr. Bowerbank alone, the perfectly astonishing number 

 of twenty to thirty species from this formation. Upwards of a 

 dozen beautifully perfect specimens of this species were most 

 obligingly sent me by Mr. Wetherell, on our mutual friend Mr. 

 Yates mentioning that I was about describing the species from 

 the Cambridge specimens, but was very anxious to render my 

 specific description complete by the inspection of more perfect 

 specimens. Mr. Bowerbank also lent me charming specimens 

 with the same object. 



Common in the London clay of Sheppey, Hampstead, Bays- 

 water, Primrose Hill, &c. 



( Col University of Cambridge, Mr. Bowerbank, Mr. Wetherell, 



