162 THE FOSSIL ECHINOIDEA 



any thing as to the form of the earlier stages of this species ; but it may be men- 

 tioned parenthetically that some small tests, which we have regarded as the young of 

 another species {Echinolampas angustifolia), may possibly belong to E. Sindensis. The 

 grounds upon which our determination is based will be found in the description of the 

 species in question ; and we at present confine ourselves to mentioning the circumstance 

 in the hope that a larger supply of material will furnish a solution to the difficulty. 



Memarks. The type of d'Archiac's species in the Museum of the Geological Society 

 is a very unsatisfactory specimen and scarcely worthy of recognition ; it also accords 

 very poorly with the description given in the text (op. cit. p. 210), and likewise with 

 the figures. Under these circumstances it would obviously be both useless and un- 

 profitable to draw any lengthy comparisons. Numerous specimens of an JEcMnolampas 

 which appears to be very common in Sind, and accords most nearly with the old specimen 

 above referred to, and which has further been regarded provisionally by the Surveyors 

 (although with doubt) as probably belonging to d'Archiac's species, are well repre- 

 sented in the collection of Khirthar fossils. It is to this form that we have assigned 

 d'Archiac's specific name, rather from unwillingness to burden the nomenclature with 

 an additional name than as an expression of our opinion as to its conformity with the 

 unintelligible and contradictory type and description of our predecessors. The form is 

 well marked, and we are unacquainted with any other species with which it can be 

 confounded. The variety hemispJicerica is also well marked^ and has not yet been 

 found associated with the type-form of the species. 



Dimensions. 



a. b. c. d. 



millim. millim. millim. millim. 



Length of the test 90 69 57 52 



Breadth of the test 75 50 48 35 



Height of the test 45 27 23 22 



Breadth of posterolateral petal . 9'5 6 6 4'25 



Locality/. In the Khirthar series of strata : Baili, west of Tong. Survey-number 



Illustrations of the Species in Plate XXIX. 

 Fig. 1, Abactinal view of the test of a large example : natural size. 



2. Longitudinal profile of the same specimen : natural size. 



3. Abactinal view of a test of the ordinary size : natural size. 



4. Actinal view of the same : natural size. 



5. Longitudinal profile of the same : natural size. 



6. Peristome and surrounding parts of the test from another specimen : 

 magnified. 



7. A portion of the ambulacral area, near the middle of a petal : magnified. 



8. Abactinal view of the test of a young specimen : natural size. 



9. Actinal view of the same test : natural size. 

 10. Longitudinal profile of the same ■ natural size. 



G304 

 23 



