LIN0PNE1 STES LONGISPIN1 S. C3 



comparatively smaller, and covered by smaller plates than in that sp 

 and is transversely elliptical. The apical system in both the spe< 

 Linopneustes is more compacl than in Paleopneustes. 



The odd anterior ambulacrum of L. longispinus is more sunken al the ambi- 

 tus than in the Japanese species. The lateral ambulacra are more petaloid 

 than iii any other species of either Linopneustes or Paleopneustes thus far 

 known; in some specimens they end at the extremity much as they do in 

 Eupatagus. (PI. XX. Fig. I.) The petaloid pores of the two rows arc of 

 nearly the same si/A', placed close together on the outer edge of the ambula- 

 cra! plates. The petals extend somewhat more than half-way from the 

 apex to the ambitus. The secondary tubercles are small, of . uniform size, 

 and the whole surface of the test is uniformly covered by minute miliaries. 

 The primary spines of the abactinal surface are long, slender, curved, (PI. 

 XIX. Fig. I. PL XX. Fig. L,) some of them measuring nearly a quarter of 

 the test in length. The thin slender and straight secondary spines are not 

 more than 3 or 4 mm. long; the thin hair-like miliary spines are nearly as 



long, and are generally curved. 



On the actinal side of the test the primary tuberculatum is close in the 

 posterior lateral interambulacral areas on one or two plates near the ambitus, 

 hut towards the actinostome the primary tubercles increase in size i PI. XX. 

 Fig. 5), ami at the same time become less numerous. The tuberculation of 

 the actinal plastron is smallest along the median line, the tubercles increas- 

 ing in size towards the outer lateral edge adjoining the broad hare posterior 



interambulacral areas. The spines of the actinal surface are shorter ami 

 more slender than those of the abactinal surface ; they are curved, and those 

 adjoining the bare posterior ambulacra! /.ones are more spathiform than the 



spines on the rest of the actinal surface. The actinostome of this species 



is comparatively smaller (PI. XX. Fig. <!) than that of /.. Murrayi, meas- 

 uring only Id mm. in longitudinal diameter in a large specimen of 105 

 mm., while in one of L. Murrayi of 85 nun. the actinostome measures 

 nearly I •"> mm. 



When alive, the tesl is pinkish or Qesh-colored, the large primary 

 spines of the abactinal surface having a yellowish tint with a whitish 

 silvery lustre. 



