26 FAUNA OF BALUCHISTAN. 



the posterior pair being the longest, the odd one the shortest; poriferous zones 

 straight, narrow, composed of small pores. 



Mouth, pentagonal, transversely elongated, surrounded by a large floseelle, the 

 details of which are effaced. 



Periproct supramarginal, rather large. 



Ornamentation not visible. 



Locality and stratigraphical position, — Mazar Drik, horizon 2«. 



Bemarks. — Although not well preserved, there is no doubt that this specimen 

 belongs to the genus Clypeolampas. It is easily distinguished from Clypeolampas 

 helios, by its low, rather depressed test, the ratio of height to length being very 

 much smaller. 



Family : EOLASTERIBJE. 



Subfamily : ANANCHYTIN^. 



Genus: HEMIPNEUSTES, Agassiz. 



\%^1 . SemipneuHes, Agassiz, Catalogue raisonn^ des esp., etc. d'Bchimdes, Annales des sciences natuielles, 



ser. iii, ZooL, Vol.| VIII, page 34. 



Test suborbicular or elliptical, slightly truncated behind ; upper surface high 

 and inflated or low and depressed, lower surface flat or slightly convex. 



Anteal sulcus extending from summit to mouth ; broad and flat at the begin- 

 ning, narrow and deep near the mouth. 



Apical disc slightly elongated, composed of four genital plates perforated by 

 large holes, and five smaller ocular plates perforated by minute holes ; the right 

 antero-lateral genital plate larger than the other, serves as madrepore plate. 



Ambulacra open and unequal ; the single one, lodged in the anteal sulcus, is 

 composed of extremely fine narrow and equal poriferous zones ; pores very small 

 and obliquely arranged in pairs. Lateral ambulacra broad, flush with the test and 

 composed of very unequal poriferous zones ; anterior zone very narrow, pores very 

 small, in horizontal pairs, posterior zone broad ; pores of equal size, inner pores 

 small and round, outer ones elongated and joined to the former by a narrow furrow. 

 Basal portion of the postero-Iateral ambulacra long, and marked by a few 

 scattered pores ; antero-lateral ones indistinct, short, and only indicated by a few 

 pores at the anterior corners of the mouth. 



Peristome near the anterior margin small and semilunar ; posterior lip strongly 

 developed and projecting. Anal opening just above the posterior margin, at the 

 upper end of a depression which deeply grooves the posterior margin. 



No fascicles. 



Tubercles of two kinds ; small homogeneous granules all over the surface ; larger 

 tubercles surrounded by a scrobicule on either side of the anteal sulcus on the upper 

 surface, and in two regions, a lateral and a central one, separated by two smooth 

 bands on the lower surface. 



