NO, 3 CASSIDULOID ECHINOIDS — KIER 85 



Periproct. — Infraniar^Miial, higher than wide, in shght adoral 

 groove. 



Peristome. — ObHque or regular, anterior. 



Floscelle. — Bourrelets well developed ; phyllodes (text fig. 70) with 

 double pores, inner pore much smaller than outer on well-preserved 

 specimens ; pore pairs arranged in an outer and inner series in each 

 half -ambulacrum with approximately 10 pore pairs in outer, 6 in 

 inner ; no buccal pores. 



Occurrence. — Keocomian of France and Switzerland. 



Location of type specimen. — Museum of Comparative Zoology, 

 Harvard, No. 772. 



Remarks. — There has been considerable controversy over whether 

 or not the peristome is oblique or regular in this species. L. Agassiz 

 (1839, pi. 8, fig. 19) figured it as regular, but d'Orbigny (1855, 

 pi. 929, fig. 6) figured it as oblique. Agassiz had two specimens in 

 his type lot, one with a regular peristome (the lectotype), and the 

 other with an oblique peristome. It is possible that the shape of the 

 peristome is variable within the species. Until a study has been made 

 of a large population of this species, it is advisable to include in 

 Pygorhynchus specimens with either an oblique or regular peristome. 



Synonym of PYGORHYNCHUS 



Botriopygus d'Orbigny, 1856, Pal. franc, Cretace, vol. 6, p. 334. Type species 

 by subsequent designation, Cotteau, 1869, Pal. franc, Jur., p. 121, Catopygiis 

 obovatus L. Agassiz. 



Remarks. — Botriopygus is a junior, objective synonym of Pygo- 

 rhynchus, having the same type species. Lambert and Thiery (1921, 

 p. 353) and Mortensen (1948, p. 143) are mistaken in considering 

 Botriopygus cotteauanus d'Orbigny as the type species of Botriopy- 

 gus. d'Orbigny did not designate a type species for his genus. Lam- 

 bert's (1898, p. 162) designation of B. cotteauanus as the type species 

 of Botriopygus is invalid because Cotteau (1869, Pal. franc, Jur., 

 p. 121) had already designated B. obovatus. B. cotteauanus is the 

 type species of Parapygus Pomel, 1883. 



Genus PYGOPISTES Pomel 



Py go pistes Pomel, 1883. Class, meth., p. 56. Type species by monotypy, 

 Cafopygus fioridns Coquand (a nomen Tm6xim)z=Pygau]ns coqiiandi Cotteau. 



GENERIC DESCRIPTION 



Small, highly inflated, with rounded margin, gently rounded sides, 

 pulvinate adoral surface with peristome and phyllodes depressed; 



