54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I44 



Genus PSEUDOPYGURUS Lambert 



Pscudopyguriis Lambert, 1911b. Ann. Univ. Lyon, ser. i, vol. 30, p. 184. Type 

 species by monotypy, Pseiidopygurus letteroni Lambert. 



GENERIC DESCRIPTION 



Large, low; apical system tetrabasal; petals II and IV slightly 

 shorter than petals I and V, petal III absent or slightly developed 

 with narrower poriferous zones; all ambulacral plates double pored; 

 peristome regular, longitudinal, pentagonal; periproct inframarginal, 

 longitudinal ; bourrelets well developed ; phyllodes double pored, with 

 three series of pore pairs in each half-ambulacrum. 



Comparison with other genera. — Pseudopygurus is very similar 

 to Pygurus (Pygurus). Pseudopygurus letteroni, the type species, 

 very closely resembles Pygurus {Pygurus) hlumenhachi Kock and 

 Dunker as shown clearly in a comparison of plate 3, figure 4 and 

 plate 5, figure i. Both species have the same shape, petal arrangement 

 in petals I, II, IV, and V, and similar phyllodes. P. letteroni differs 

 only in having a less developed petal III. 



Range and distribution. — Besides the type species from the Se- 

 quanian of France, Petitot (1954) has described a species, P. am- 

 broggii, from Oxfordian of Algeria, and Checchia-Rispoli (1941) 

 has figured and described, but not named, another species from the 

 Sequanian of Italian Somaliland. 



DESCRIPTION OF TYPE SPECIES 



PSEUDOPYGURUS LETTERONI Lambert 



Plate 5, figures 1-4; text figure 28 



Psettdo pygurus letteroni Lambert, 1911b. Ann. Univ. Lyon, ser. i, vol. 30, 

 p. 184 (footnote). 



Material. — Lambert never figured this species. There are four 

 specimens in the Lambert Collection. The specimen marked type is 

 herein designated the lectotype and is figured in plate 5, figures 1-4. 

 It is well preserved adapically and clearly shows the petals, but 

 adorally the peristome is covered with matrix, and the periproct 

 obscured. A second specimen, also in the Lambert Collection, from 

 a different locality is badly pitted but shows the peristome and 

 periproct. 



Shape. — Large, low, greatest height anterior at apical system, 

 greatest width posterior of center, anterior margin blunted, posterior 

 pointed, outline roughly pentagonal. Adapically, interambulacrum 5 



