OF KACHH AND KATTYWAE. 15 



De Loriol has kindly sent us an unpublished work on the Eocene Echinida of 

 Egypt and Lybia, and it contains a notice of A. dilatatus. It gives the following mea- 

 surements : — Length 56 millim. ; relative length to breadth as 1 : 0-91 ; length to 

 height 1 : 0-41. The obliquity of the peristome is admirably shown. 



Dr.. W, Dames, in his work on the Echinoidea of the Tertiary strata of the 

 Vicentin and Verona (' Palaeontographica,' Cassel, 1877, p. 26), briefly but none the less 

 clearly disposes of the species Amblypygus apheles from Verona, and states that it is an 

 elongate form oi Amblypygus dilatatus. He finds that Laube, in his 'Echinid. d. vie. 

 Tert.' p. 20, wrongly attributes Amblypygus apheles to a form from the Vicentin, it 

 being Amblypygus dilatatus, and he notices that this widely distributed species has not 

 always a sharp margin. 



Cotteau, 'Echinides des Pyrenees,' p. 109, gives the generic diagnosis oi Amblypygus, 

 and adds that the ambulacra! pores are oblong and conjugate, that the tubercles are 

 close and homogeneous, and that there is no floscelle. 



He named a species Amblypygus Michelini; but Leymerie has found that this form 

 has a subpentagonal peristome with a floscelle. Cotteau states that this renders the 

 generic position of the form uncertain, and that it may be a true Echinolampas. 



The so-called Amblypygus from Malta does not belong to the genus. 



It appears from these data that the species Amblypygus apheles and Amblypygus 

 Michelini are worthless. Amblypygus dilatatus, Agass., described by De Loriol, 

 is the type of the genus, and the obliquity of the peristome noticed by him becomes there- 

 fore a generic character. Desor states that the actinal surface is concave ; but it is 

 swollen and convex, except around the peristome, where there is a decided concavity (in 

 the position of the test on its back). 



Desor states that Amblypygus Arnoldi, Agass., and Amblypygus Americanus, Mich. 

 MSS., have the same appearance, and that A. Arnoldi is uniformly swollen and has a 

 thick margin j so that, according to our description oi Amblypygus Americanus, A. Arnoldi 

 must be a depressed form, having the relation of length to height as 1 : 0*43. Its 

 poriferous zones are " tres etroites." 



The form described by Dr. Wright, F.E.S., from Malta, is not an Amblypygus. 



The species properly included in the genus Amblypygus up to the present time 

 are Amblypygus dilatatus, Agass., A. Arnoldi, and A. Americamos. 



They belong to a group with specimens having the relation of length to height as 

 1 : 0-4 and 1 : 0-43. 



The chief characteristic of the specimens from Kachh is their great relative height 

 and disposition to a pentagonal outline. 



There are three well-preserved specimens, and one which is within 5 millim. 

 of the length of Egyptian Amblypygus dilatatus is 10 millim. higher. The relative 

 dimensions are: — Kachh form, length to height 1 : 0'62. 



The range of relative length and height in the Kachh forms varies, in perfect speci- 

 mens, from length 1 : 0-62 to 1 : 0-63. 



Moreover, the Kachh forms are longer than broad. Hence it is evident that the 

 Kachh Nummulitic specimens belong to a new species. 



