14 SMITHSOXIAX MISCELLAXEOUS COLLECTIOXS VOL. 53 



Order PROPARIA Beecher 

 BuRLixGiD.15, new family 



Dorsal shield small, elongate, broad oval in outline. Cephalon 

 about one-fourth the length, transversely semicircular : genal angle 

 acute or spinose ; glabella with transverse lobes. Free cheeks small, 

 separate. Facial sutures cut the margin in' front of the genal angles, 

 extend in to the posterior portion of the eye lobe and outward from 

 the anterior portion to the antero-lateral margin of the cephalon. 

 Eyes of medium size, clearly defined. 



Thorax with fourteen segments in the one species preserving them ; 

 pleura; with flat, straight furrows. 



Pygidium large, with strong axis and pleural lobes, or small and 

 with medium axis and pleural lobes. 



Stratigraphic Raxge. — Central portion of the Middle Cambrian 

 to the Agiiosfiis pisifonnis zone of the Swedish Upper Cambrian. 



ObsErvatioxs. — This family includes the genera Biirlingia and 

 Schmalcnsceia} The first is represented by entire specimens and the 

 latter by the cephalon, fragments of the thorax, and entire pygidia. 

 The facial sutures and free cheeks relate Biirlingia to some forms of 

 the Cheirurid?e, while the pygidium of Biirlingia recalls the simple 

 pygidium of Paradoxidcs, and the pygidium of Schnuilcnsccia recalls 

 that of Aiuphioii. The flat, straight furrowed pleurae of the thorax 

 of Biirlingia recall the pleurse of Olenoidcs. The assemblage of 

 characters in Biirlingia and Schnialcnsccia clearly indicate a distinct 

 family of the Proparia, more primitive than any other forms of that 

 order. 



BURLINGIA, new genus 



Dorsal shield small, elongate, broadly oval. Cephalon semicir- 

 cular; one-fourth the length of the entire shield; genal angles with 

 spines ; cranidium- with anterior and posterior limbs that extend out- 

 ward from the glabella to the outer margin ; glabella slightly convex, 

 with indications of lobes. Free cheeks subquadrangular, small. 

 Facial sutures extend from in front of the genal angles inward to 

 the eyes and then obliquely outward and forward, cutting the antero- 

 lateral margin. Eyes of medium size. 



Thorax with fourteen segments ; pleurae with a flat, direct furrow ; 

 pleurae extended into backward-curving, falcate extremities. 



' Moberg, 1903, Meddelande fran Lunds CtCoI. Mineral. Inst. No. 5 (Geol. 

 Foren. i Stockholm Forhandlingar, Bd. xxv. Haft 2, 1903, No. 219), p. 96. 



" The cranidium includes all portions of the cephalon except the free checks 

 and eye lobes. 



