ON OUlt PRESENT KNOWLEDGE OF THE CUUSTACEA. 193 



A seventh group occurs on the Town Estate, Victoria Road, Leicester. 

 The largest boulder is 2 feet 9 inches x 2 feet x 1 foot 10 inches, and the 

 smallest 1 foot 8 inches x 1 foot 6 inches x 1 foot. The boulders are 

 angular, and without striations. Rocks of the same nature occur at 

 Groby and Markfield, a distance of five miles and seven miles N.W. 

 They are composed of syenite, and are 260 feet above the sea, covering an 

 area of 30 yards x 10 yards. They have been exposed in excavations. 



An eighth group occurs at Clarendon Park, near Leicester. The largest 

 boulder is 2 feet 6 inches x 1 foot 5 inches X 1 foot 7 inches, and the 

 smallest 1 foot 9 inches X 1 foot 5 inches x 10 inches. Three are rounded, 

 others are angular and sub-angular, but the rounded edges may have 

 been done in situ. All have been moved out of excavations ; no striations. 

 Rocks of the same nature occur at Mount Sorrel at a distance of seven- 

 and-a-half miles N.N.W. The boulders are all composed of syenitic 

 granite, and are 300 feet above the sea, covering an area of 20 yards x 10 

 yards. 



Report on the Present State of our Knoiuledge of the Crustacea. — 

 Part IV. On Development. By C. Spence Bate, F.R.S. 



[Plates V., VI., & VII.] 



Having, during the last three Reports, given an account of the present 

 state of our knowledge of the dermal skeleton of the higher forms of 

 Crustacea as it appears in various genera in the adult animal, it is 

 desirable that we should next obtain some knowledge of the forms that 

 these animals undergo in their passage from the ovum to the adult. 



It is highly probable, judging from the very perfect resemblance to the 

 parent form that the animal attains while yet young, that the earlier 

 zoologists believed them to quit the egg in this condition. For when Bosc 

 took in mid-Atlantic the small animal which he christened Zoe, he never 

 for a moment thought that it was the young of some other form. 



It was in 1802 that it was first described, and ranged by the author 

 between the Branchiopoda and Amphipoda. But Latreille, in the first 

 edition of the ' Regne Animal ' of Cuvier, placed it at the. end of the 

 Branchiopoda, between Polyphemus and Cyclops, while expressing an 

 opinion that it approached nearly to the Schizopoda. 



Leach seems to have held this same opinion, for without giving his 

 reasons, he placed it at the end of the legion of Podophthalma, by side 

 of Nelalia. 



Desmarest, in his ' Consid. sur Crustaces,' places it in the order 

 Branchiopoda, near Branchipes, while Latreille ranks it with " Monocles," 

 while Milne-Edwards ranges it, with doubt, at the end of the Decapoda, 

 with other questionable genera, after the Schizopoda, and before the 

 Stomapoda. 



In 1830 Vaughan Thompson took a zoaea in Cork harbour that while 

 in his possession passed into the Megalopa stage, which induced him to 

 assert that zoasa was nothing more than the larval stage of one of the 

 crabs common to our shores. 



This idea was much doubted by the naturalists of the day, more 

 1878. o 



