OF WESTERN SIND. 39 



plate ; they are rather large, and some perforate the ridge which passes from the ambu- 

 lacral raised ridge to that of the interradial area. The interambulacra are broad, and 

 have two vertical, narrow, raised ridges, on which are placed the twelve small primary 

 tubercles. The ridges are rounded, sometimes have a single granule here and there ; 

 and the tubercles are largest near the ambitus, being very faintly perforate and crenu- 

 late, and occasionally surrounded by a circle of small miliaries. The median inter- 

 ambulacral space is occupied by a zigzag of slightly curved, narrow, rounded ridges, 

 smaller than those of the vertical series, and extending from the tubercles of one series 

 to those of the other in oblique paths. These ridges sometimes carry a large granule 

 or two. 



The coronal plates are very visible between the cross ridges, and the sutural lines 

 are very distinct. Like those of the ambulacra, the sutures do not mark the. ridges in 

 the larger specimens, but they cross them in the younger. Between the interradial 

 tubercles and the ambulacra there are groups of two or three ridges passing obliquely 

 off from each tubercle ; these pass between the poriferous plates, and are sometimes 

 perforated by the pores, and finally unite with the adjoining vertical ridge of the 

 ambulacrum. 



Height of test -j^ inch, breadth ^ inch. 



Locality. North by east of Petiani. Eanikot series. Survey-number G f |f . 



Illustrations of the Species in Plate IX. 

 Fig. 1. The test of Dictyopleums ziczac : natural size. 



2. The apical system : magnified. 



3. An ambulacrum and interradial area : magnified. 



2. DiCTTOPLEUEUS Haimei, sp. nov. Plate IX, Figs. 4, 5. 



The test is small, tumid at the ambitus, which is circular in outline, conical above, 

 rather flat actinally, and sunken at the small peristome. Apical disk wanting, but its 

 direction appears to have been oblique. The ambulacra are much narrower than the 

 interradial areas ; the poriferous zones are narrow, and consist of a continuous single 

 series of pairs of pores, which usually penetrate ridges connected with the interradial 

 tubercles. There are three pairs of pores to each interradial plate. Immediately within 

 the series of pores is an indistinct raised ridge ; it is vertical, thin, straight, and discon- 

 tinuous, here and there carrying very small tubercles ; these are largest near the actinal 

 surface, and have swollen bosses and small mamelous. Crossing the space, in the inter- 

 poriferous region, between these vertical ridges is a series of oblique narrow ridges, 

 sometimes linear, at others thicker, and ornamented with one or two rows of miliaries. 

 These pass from one tubercle to those of the opposite series above and below; 

 and there is distinct space between them in which the sutures can be seen. Here 

 and there the zigzag becomes disorderly. 



The interambulacral areas have two vertical narrow ridges, one on each coronal 



g2 



