BiT THE KEY. DK. WOOLLS, D.D., F.L.S., ETC. 493 



the other is found " where the rock approaches in its granular 

 character to the nature of sandstone." The latter appears to me 

 to be £. macrorrJii/ncha, as the seed vessel is reported to attain a 

 large size, but in order to form any definite opinion of geological 

 influences, the whole matter needs careful investigation. 



On a youxg specimex of a Temnopleurxis. 



By the Eev. J. E. Texison-Woods, F.G.S., F.L.S. 



[Plate XV., figs. 3, 4, and 5.] 



The species here described was dredged up from a few fathoms 

 at Port Denison. It appears to me to belong to the genus 

 Temnopleurus, and as far as I can judge belongs to a new species. 

 It is principally distinguished by the extent and depth of the pits 

 on the coronal i)lates. Unfortunately there are no perfect 

 specimens and the anal system is entirely wanting. There are 

 two single rows of large tubercles (primary) in each area, and 

 secondaries are scattered in irregular double lines on the ridges 

 between the sutural pits. On the ambulacral area this line is 

 close to the pores, which are a single row of double pores. On 

 the interambulacral area there is a very irregular line of 

 secondaries between the line of pores and the row of primaries. 

 The tubercles have a conspicuous smooth base and a rather large 

 area which is also smooth. The sutural pits are regularly oval, 

 and equally deep. The shape of the test is circular and depressed 

 not conical. The actinosome is large, round, without cuts and 

 the arches are broad, rather high, solid, united above and 

 connected with one another by hood processes. 



Prof. A. Agassiz has given us such full information about the 

 young stages of Temnoplcurus that we are able to pronounce at 

 once upon any small urchins belonging to the genus. The 

 specimen in question does not belong to T. Hardwichii, as in that 

 species the sutural pits are altogether wanting on the actinal 



