NO. 3 CASSIDULOID ECIIINOIDS — KIER 39 



open or slightly dosed, equal length, petaloid pores conjugate, outer 

 pore slitlike, all ambulacral plates double pored ; periproct marginal 

 to inframarginal, oval, longitudinal, with slight groove extending 

 adorally; peristome slightly anterior, pentagonal, width equal to 

 length, bourrelets well developed ; phyllodes slightly broadened, long, 

 double pored, with two or three series of pore pairs in each half- 

 ambulacrum ; no buccal pores ; tubercles on adoral surface slightly 

 larger than on adapical. 



Comparison with other genera. — Dothryopneustes is very similar 

 to Clypeus, having the same petal arrangement and shape of test, 

 and similar floscelle. It differs from Clypeus in having its periproct 

 marginal to inframarginal, whereas it is supramarginal in Clypeus. 

 Furthermore, the test is usually smaller in Dothryopneustes. As an 

 example of the great similarity of the two genera, Currie's Clypeus 

 wylliei (pi. 8, figs. 2, 3) and Bothryopneustes sonialiensis (pi. 9, 

 figs. 7-10), both from the same bed in British Somaliland, are almost 

 indistinguishable except for the location of the periproct. 



Remarks. — Lambert (1932, p. 184) referred his Phyllobrissus 

 joiirdyi to Bothryopneustes, but its petals are only slightly developed, 

 not broad as typical in this genus. 



Range and distrihuiion. — Jurassic (Bathonian to Callovian) of 

 Africa and Madagascar. 



DESCRIPTION OF TYPE SPECIES 

 BOTHRYOPNEUSTES LAMBERTI Fourtau 



Plate 9, figures 1-4; text figures 18-20 



Bothryopneustes lamherti Fourtau, 1924. Cat. invertebres foss. I'^lgypte, terr. 



Jurassiques, pt. i, fichinodermes, pp. 28-29, pi. 2, fig. 5. 



Material. — Holotype and five paratypes studied. 



Shape. — Small to medium, 16 to 30 mm. long, elongate, anterior 

 margin blunted, posterior slightly pointed, greatest width posterior 

 to center, low, adorally peristome, ambulacra depressed. 



Apical system.—S\\gh.i\y anterior, tetrabasal (text fig. 19), genital 

 plates pointed at extremities. 



Ambulacra. — Petals broad, open to slightly closed, long, extending 

 to margin, interporiferous zones wide, at greatest width almost twice 

 width of poriferous zones, slightly inflated; poriferous zones narrow- 

 ing distally, petaloid pores conjugate, outer pore greatly elongated 

 transversely, slitlike, inner pore slightly elongated. 



Adoral interambulacrum.—Single plate at peristome (text fig. 18) 

 preceded by double series of alternating plates. 



