Lower Tithonian mono- and dicyrtid Nassellaria (Radiolaria) from the Solnhofen area (southern Germany) Author Dumitrica, Paulian Institut de Géologie et Paléontologie, BFSH 2, UNIL, CH- 1015 Lausanne (Switzerland) Paulian. Dumitrica @ igp. unil. ch umitrica@igp.unil.ch Author Zügel, Peter Geologisch-Paläontologisches Institut, Johann Wolfgang Goethe-Universität, Senckenberganlage 32 - 34, D- 60054 Frankfurt am Main (Germany) zuegel @ em. uni-frankfurt. de. text Geodiversitas 2003 25 1 5 72 journal article 10.5281/zenodo.5372196 1638-9395 5372196 8BF4D0FF-F247-4B92-B327-0D647B01C386 Cassideus deweveri n. sp. ( Figs 21E, F ; 22 ) HOLOTYPE . — Photo No. 58119; stub Mue 22/20; Musée de Géologie , Lausanne, No. 74397 ( Fig. 21E ) . PARATYPES . — MNHN , bât. de Géologie, No. Gg 2001/2100-2101. ETYMOLOGY. — The species is named for Prof. Patrick De Wever (MNHN) to honour his valuable contribution to the knowledge of Mesozoic and Paleozoic radiolarians. MATERIAL EXAMINED. — Four specimens from the type horizon (sample Mue 22). DIMENSIONS ( IN µM). — Height of test without horns 118-125, of proximal part 47-50, of middle and distal part of thorax 55-65, of skirt 20-30, diametre of thorax at the boundary between proximal and middle part 65-75, at the boundary with skirt 90-92, maximum diametre of skirt 118-130, length of apical and ventral horns 60-65. DESCRIPTION Test high, conical, with apical and ventral horns robust. Apical horn curved, obliquely upward directed, ventral horn straight or very weakly curved, inclined about 30° above the horizontal plane. Both bladed proximally and massive medially and distally. Cephalis with small pores, externally undistinguished from the proximal part of thorax with which it forms a low cone. Middle and distal part of thorax high conical to subcylindrical, straight or weakly constricted medially, well separated from the proximal part and thoracic skirt by the change in outline, and having nine to 10 transverse rows of alternate pores. Thoracic skirt expanded at an angle of about 50° below the horizontal plane and bearing four to six transverse rows of alternate pores. REMARKS Cassideus deweveri n. sp. resembles C . biannulatus n. sp. by having a rather similar shape and two robust horns but differs from it by being slightly higher, by the lack of two circumferential thoracic ridges, and by the less expanded thoracic skirt.