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Ostracoda, and mostly found, and in no scanty number, em- 

 bedded in the nodular concretions, fitly named after tbem, the 

 Entomostraca nodules. 



These tiny Crustacea have as associates numerous other 

 microzoa, and measure in length 1.5 mm. by 1.0 mm. in width. 

 We would observe in passing, by way of comparison, that the 

 largest specimen of Ostracod known, was brought home last 

 year from the Challenger expedition, dredged from a depth of 

 16,000 fathoms in the South Indian Ocean. Its length was 

 22 mm. by 16 mm. wide. My friend. Professor Rupert Jones, 

 of the Sandhurst Staff College, kindly examined the Church- 

 down species. In his report, he says — " That he has been too 

 busy to do more than give generic accounts of those I mounted 

 for determination. . He finds Cyprides, Cythrelloe, and Cytheroe, 

 and adds, that they are most interesting in every point of view, 

 that he is going to have some of them figured to aid him in a 

 more vigorous determination, and recommends me by all means 

 to go on collecting from these Entomostraca nodules." I am also 

 kindly promised help in working them out, by Professor Hughes, 

 F.G.S., of the Woodwardian Museum, Cambridge, so that for 

 these results we must patiently wait. The Grinoids must next be 

 treated on. They abounded in liassic seas, but generally 

 flourished on a deeper sea-bottom than the Spinatus sands occu- 

 pied. Legions of the ossicula of Pentacrinites with like remains, 

 rich and rare, drifted from other depths and lodged in the tangle 

 banks of the Spinatus Zone. Of the dismembered Grinoids, 

 some which I have entered in the general list of the fauna, 

 have hitherto been scarcely known, if at all, to English science, 

 such as the Pentacrinites placenta, P. subteroides, Quenstedt, and 

 many varied forms of P. basaltiformis. One of them, the P. 

 nudus, Schlonbach, is simply a smooth variety of P. basaltiformis. 

 Lastly, among other organisms that inhabit these sands are 

 some of more significance, as they confirm our view that the 

 position of the Spinatus sands was in the Laminarian Zone of 

 depth. These are univalve shells lying on and among the sea- 

 weeds. On the cleavage surfaces, and lying among the stems 

 of the Tangles and other algoe before mentioned, are hordes of 



