12 THE TERTIARY FOSSIL ECHINOIDEA 



the apical system ; but the rise of the test is very slight in relation to its breadth. 

 There is no marginal swelling. Apical system absent. The ambulacra are subequal, 

 and end marginally within one third of the distance from the edge to the apical system. 

 The interporiferous zones are broad and the poriferous are narrow, and instead of 

 approaching distally are wide apart and everted, so as to become more distant at their 

 ends than at a Kttle way within the petal. The pores are subequal, the test is thin, 

 and the needle-pillars are numerous. 



Length from front to apical system 45 millim. ; greatest breadth 85 millim. ; height 



17 millim. 



Locality. Nummulitic series, west of Junagia, north of lera. Survey-number 



C 060 A f. 



Illustrations of the Species in Plate VI. 



Fig. 6. The upper part of the test : natural size. 

 7. Ornamentation: magnified. 



Suborder ATELOSTOMATA. 

 Family CASSIDULIDM 



Subfamily ECHINONEIN^, Agassiz, 1847. 



Genus AMBLYPYGUS, Agassiz, 1840. 



Amongst the collection of Echinoidea from the Nummulitic strata of Kachh which 

 was obtained by the Geological Survey of India are several fine specimens of the genus 

 Amblypygus. The condition of preservation of the specimens is very good, and we are 

 enabled to offer a description of the structural details of their tests, which it is hoped 

 will assist palaeontologists to comprehend the well-marked genus better than they have 

 hitherto been able, in consequence of the imperfect condition of most European, 

 African, and American specimens. 



Probably the descriptions and illustrations of these forms from Kachh will influence 

 the classificatory position which has hitherto been assigned to the genus Amhlypygus. 



The genus is not represented in the lower Nummulitic series of Sind, called the 

 Ranikot series. On searching amongst the collection of the Echini from the regions 

 of Sind and Kachh, in the Museum of the Geological Society of London, we found a 

 form from Kachh from a Nummulitic horizon at Babua Hill, and which was described 

 as Qalerites pulvinatus, Sowerby, in a memoir by Captain Grant, Trans. Geol. Soc. 

 vol. V. part 2 (read 1857), tab. xxiv, fig. 26. 



This specimen has its actinal surface hidden, and therefore nothing but guesses 

 could be employed in attem.pting its generic position. Desor, in his 'Synopsis des 

 Echinides,' page 321, classifies this form in the genus Conoclypeus, and states that it is 

 a large Urchin with a circular outline and hemispherical. The petals are long and 

 open. The length 3^ inches, and the height 1 inch. He considered that it was allied 

 to Conoclypeus Duboisii, Agass., of the Crimea and the Bavarian and Swiss Alps. 



On comparing this very badly preserved specimen with those which are about to 

 be described, there is no doubt that it belongs to the genus Amhlypygus. Never- 



