﻿210 BRITISH FOSSIL CRUSTACEA. 



J. Vander Hoeven had contributed a valuable memoir 1 on the sole other surviving 

 representative of the Xiphosura, the Limulus Moluccanus. 



An excellent account of the general anatomy of Limulus polyphemus will also be 

 found in Professor Huxley's lectures on the Invertebrata 2 (1857). Professor Gegenbaur's 

 researches on the anatomy of Limulus appeared a little later in 1858. 3 



The liberality of the French Government in publishing the results of researches 

 carried out by the scientific expedition to Mexico in 1867 (although much delayed by the 

 siege of Paris), enabled Professor Alphonse Milne-Edwards to produce in 1873 4 a 

 monograph on the anatomy of Limulus polyphemus most admirably illustrated by twelve 

 folio chromo-lithographic plates, which for colour and excellence leave little to be 

 desired. We shall make further references to these memoirs as we proceed. 



Exuviation and Replacement of Lost Appendages. 



We are indebted to the Rev. S. Lockwood, Ph.D., for a series of most valuable 

 observations on the American "Horse-foot Crab," Limulus polyphemus, Latr., carried on 

 at Rariton Bay, New Jersey, U. S. A. 5 



According to Dr. Lockwood, the exuviation of the King-crab is performed several 

 times during the first year of its life, and at very short intervals, varying according to 

 the time of hatching. Dr. Lockwood believes that the young Limuli which are hatched 

 in the latter part of June will complete five or six moults before the winter sets in. 

 Even in the case of the adult King-crab he thinks it probable that the shell is cast 

 more than once in the year. He mentions the capture of an adult female Limulus in 

 the Oyster Dredge, during a fine open February, in Rariton Bay, which had just shed its 

 shell and was still quite soft. Like all other Crustacea it moults more frequently 

 during the earlier and more rapid period of growth than afterwards. 



Limulus being a great burrower he not unfrequently disturbs the bivalve Mollusca 

 in their submarine retreats. Dr. Lockwood mentions an instance of a Limulus which 

 had either accidentally trodden upon or had wilfully seized the projecting siphons of a 



1 'Recherches sur l'Histoire Naturelle et l'Anatomie des Limules,' 1838, Leyden, 4 to, pp. 48, 

 7 plates. 



2 "Report of Lectures delivered at the Royal School of Mines," 'Medical Times and Gazette,' 1857, 

 vol. xv, p. 188. See also his recently published volume, 'A Manual of the Anatomy of Invertebrated 

 Animals,' small 8vo, London, 1877, pp. 700. 



3 Gegenbaur, " Anatomische Untersuchung eines Limulus, mit besonderer Beriiksichtigung der Gewebe" 

 ('Abhandl. d. Naturf. Gessellsh. zu Halle,' Bd. 4, Hefte 2 u. 3, 1858, p. 227). 



4 ' Etudes sur les Xiphosures et les Crustaces de la Region Mexicaine,' cinquieme partie, Paris, folio 

 (1873), pp. 44, 12 coloured plates. 



5 Communicated in October, 1869, to the ' New York Lyceum of Natural History,' and subsequently 

 printed in July, 1870, in 'The American Naturalist,' vol. iv, No. 5, p. 257. 



