41 C) Proceedings of the Royal P/ii/sienl Sociehj. 



examples of E. elegans which I have seen. The colour is a very 

 dull red, difiused over the test, and not arranged in definite bands ; 

 the spines are white, and those on the abactinal surface have a dull 

 greenish band at the base, recalling the spines of P. acutus. How 

 far these characters would serve to distinguish the species I will 

 not venture to say. According to Bell's measurements the mouth 

 in E. microstoma seems to be about one-fourth the diameter of the 

 test, whilst in E. elegayis it is on the average nearly one-third. 

 According to Sir Wyville's figures the jaws present some points of 

 distinction, though these can hardly be of general utility for 

 practical discrimination. 



Distribution. 



British Seas. — Off west coast of Scotland and Ireland, 150-400 

 fms. (Thomson, 2). Off the mouth of the English Channel, 

 "Porcupine" (1870), St. 1, 5G7 fms., and St. 3, 690 fms. 

 (Thomson, 1). Off Valentia (OoU. Norman, from "Porcupine" 

 Exp.). S.-W. Ireland, 110-500 fms. (Bell, 3). 



Other Localities. — Bay of Biscay (Norman, 3). 



15. Echinus norvegicus, iJilben & Koren. 



1844. Echi7i2is norvegicus, Diiben & Koren, Skaiul. Echin., p. 268, 



pi. ix., figs. 33-39. 

 1872. ,, ,, Agassiz, Kev. Ecliin., pp. 125, 296, 496, 



pi. via, fig. 4. 



Diagnosis. 

 Test usually not exceeding 15 mm. (06 in.) in diameter 

 (largest recorded 50 mm. = 2 in.) ; flattened conical in the larger 

 specimens ; five red broad bands or blotches surround the anus ; 

 rarely some or all these blotches are divided, doubling the number 

 of red lines ; primary tubercles in ten conspicuous rows in the 

 larger specimens ; some of the primary tubercles have often dis- 

 appeared in the aboral surface ; spines of uniform colour ; primaries 

 much more than half the diameter of the test in specimens of 

 average size. 



Distribution. 



British Seas. — Off the Butt of Lewis, warm area, " Lightning,'* 

 St. 12, 530 fms. Fceroe Channel, cold area, " Porcupine " (18G9), 

 Sts. 62-G6, 125^640 fms. (Thomson, 1). " Knight Errant," St. 1, 

 35 fms., St. 7, 530 fms. (Agassiz, 4). Shetland, 40-100 fms. 

 (Forbes, 2). Outer Skerries Haaf, off Whalsey Lighthouse, 70 

 fms.; Unst Haaf, St Magnus Bay (Norman, 1). E. of Shetland, 



