MUSEUM OF COMPARATIVE ZOOLOGY. 271 



cellar:a3 among Spatangoids are not found in fascioles at all ; they are 

 found round the mouth principally, and also on the surface of the test. 

 The plates of the anal system, arranged in three rows, are broader and 

 longer than in "the Pacific species, where they are arranged in two rows 

 only, the outer row being the largest. In the pacific species the pits of the 

 smooth band are reduced to a few indistinct impressions, the whole band 

 being thickly covered by minute silk-like spines. The floscelle is most dis- 

 tinct also, while, owing to the sculpture of the bare band round the mouth 

 in the West India species, its outline cannot be traced. 

 Fragments in 106 fathoms. 



Neolampas rostellatus A. Ac, nov. gen. et sp. 



Outline from above resembling Echinolampas more elongated, three 

 large genital openings ; the left anterior one atrophied, placed closely to- 

 gether, madreporic body restricted to a narrow ridge separating them. 

 Seen in profile, the test rises gradually from the anterior extremity to- 

 wards the apical system, attaining its greatest height between it and the 

 posterior extremity ; this is sharply truncated anteriorly, as in some species 

 of Catopygus. The lower extremity is concave, undulating ; the anal sys- 

 tem is large, elliptical, occupying the whole of the posterior truncated end, 

 somewhat as m Botriopygus, the test being turned in like the finger of a 

 glove, while the anus opens at the end of a long slender tube, extending 

 well beyond the outline of the test, starting from the upper part of the anal 

 membrane, which is covered by small plates, gradually diminishing in size 

 and eventually firmly soldered together to form the base of the anal tube. 

 Test thin, mouth placed near anterior extremity, having a well-developed 

 floscelle and prominent bourrelets. The test is covered by minute tubercles 

 of different sizes, not separated into primaries and miliaries, as*in Echinolam- 

 pas. The tubercles are not sunk, but stand out prominently from the test. 

 The spines are straight, very fine, resembling those of the Scutellida?. 

 There is no ambulacral rosette so prominent in all Echinolampadas. From 

 an external examination alone it would be difficult to trace the course of 

 the ambulacra, but from the interior we easily see one pore for each am- 

 bulacral plate extending from the floscelle to the apical system, and appear- 

 ing as most minute pores when seen from outside. In fact, the structure of 

 all the ambulacra is here identical with the structure of the ambulacra be- 

 tween the rosette and the mouth in other Echinolampadae. The color of 

 this Sea-urchin is a yellowish green, and I am convinced it is not the young 

 of any other Echinolamp, in spite of its size (^ of an in.), owing to the great 

 development of the bourrelets, which in other Echinolampadaj appear only 

 after the specific characters are fully formed and the main features of the 

 adult attained. 



From 100 to 125 fathoms. 



