318 



E0HTNODERM8 OK THE BRITISH ISLES 



1. Family Cassidulidk 



Diagnosis same as that of the order. ^ 



Only one genus, Neolampas, known to occur in the British 

 (and European) seas. Two more genera, EcJiinolampas Gray and 

 Conolampas A. Agass., are represented in the West Indian deep 

 sea. It is not improbable that they will prove to occur also in 

 the North-eastern Atlantic, but as yet they have not been found 

 there, and therefore cannot be included here. 



1. Neolampas A. Agassiz. 



Test elongate. Ambulacra simple, not petaloid on upper side 

 and only slightly so at the peristome. Mouth more or less 

 anterior. Anal opening at the posterior end of test, in a small 

 depression, above which the test forms a small prominent edge. 



Only one species in the British (and European) seas. 



1. Neolampas rostellata A. Agassiz. (Fig. 184.) 



Test low ; on the upper side the posterior interambulacrum 



on the under side distinctly sunk 



forms a rather distinct keel 



Fig. 184. — N eolampas rostellata. x 3. (1-2. After Agassiz, " JSZal'e " E'c/jim'. 

 3. After Wyv. Thomson, " Porcupine " Echinoidea.) 



1. Denuded test, from above. 2. Same, from below. 3. Side view of specimen with tlae 

 spines partly preserved. 



towards the mouth. Only 3 genital pores ; in the male they 

 are of about the same size as the ocular pores, in the female they 

 are much larger. Only few pores in the madreporite. Colour in 

 life unknown. Apparently not exceeding ca. 20 mm. length. 



1 It is not unlikely that the recent forms known of this order ought 

 rather to be referred to different families. This question, liowever, cannot 

 yet be regarded as sufficiently elucidated. 



