60 CALIFORNIA ACADEMY OF SCIENCES. 



A. (Cr.) caractacl Murch., A. fimbriatus Murch., A.radiatus Murch., 

 A. lloydii Murch. 



IX. Odontocephahis u. g. O. ovaia u. sp. Calymene arachnoidea Goldf. 

 Cryphaus Green. 



The author figures Phacops rotundi/roun, Conocephalus .ttriatns, Odonto- 

 pleiirn ovata, Crypiolithiis caractaci aud Asaphn.s glohicepx. 



Zur Naturgeschichte der Trilobiten. Pro- 



gramm zur offentlichen Priifung, welche mit den Zog- 

 liiigen der Realschule in Meiningeii Donnerstag dem 

 28, und Freitag den 29." Marz 1844 im grossen Horsaale 

 der Anstalt abgehalten werden soil, etc. Meiningeii, 

 1844, 1 pi. 



Pt. 1. Zur Moi-phologie der Trilobiten, pp. 4-13. 



Pt. 2. Ueber die Trilobitengattungen, pp. 13-18. 



Pt. 3. Ueber die Verbreitung der Trilobiten in den Gebirgsschichteu, 

 pp. 18-28. 



The genera are arranged into 25 families in the following order: 



A — Phacops in the restricted sense (Calymene Brong. in part). Con- 

 tractile. PleurjB rounded at the extremity, with an acutely-sharpened 

 anterior margin. Axis of pygidium furnished with 11 or fewer joints. 

 P. macrophthalmus Brong., protnberans Dalm., cryptophthatmtis Emm. 

 (Calymene Icevis Miinst.?), scleropt Dalm. (powisli Murch.), conophthalmus 

 Boeck., doioningkv Muroh., proceviva Emm., rotnndi/rons Emm. 



B — Dalmania (Asaphus Brong. in i)art, Asaphus Goldf.) Not contractile. 

 Pleura at the anterior margin scarcelj' sharpened, frequently acute. Gla- 

 bella always clavate, distinctly lobed. Pygidium with more than 11, 

 sometimes as many as 22, joints to the axis, frequently elongated at the 

 extremity of the tail. Phacops caudatus Briinn., mucronatus Brong., 

 hausmanni Brong., odontocephalus Green., trnncato-caudatus Port. 



II. Phillipsia Port. Facial suture extending to the posterior margin. 

 Glabella almost cylindrical. Thorax 9 to 10 jointed. 



(a) Nine-jointed species: Phacops kelli, jonesil, ornata. 



(b) Ten-jointed species: Asaphus dalmani Goldf. Calymene (pqualis 

 V. Mey. 



Family II. Asaphi in the restricted sense. Contractile species. Pleuraj 

 always sharpened at the anterior margin, generally obtuse at the extremity. 



III. Griffithides Port. Glabella gibbous, clavate. Thorax 9- jointed. 

 Pygidium furnished with 10 joints and upwards. G. glohiceps, longispivm 

 Port., obsoletus Phil. 



IV. Gerastos Goldf. (Proetus Stein.) Glabella truncate, cylindrical, 

 indistinctly lobed. Thorax 10-jointed. Tail less and indistinctly jointed. 

 G . concinmis Dalm. 



