BIBLIOGRAPH'/ OF PATj.EOZOIC CRUSTACEA 77 



RAYMOND (Percy E)— Continued 



ginatus Billings (syn. B. minganensis J}ill.), B. iilanJicephalus Wliitf., B. angdini 

 Billings, B. actitus sp. nov., B. arcuatus Bill., B. spiniger Hall, B. iitgaUi sp. nov. and 

 B. schucherU Clarke. 



With Bathyurus mem Bill., for a type the author proposes the new genus Petiguriis. 



The genus is closely allied to Bathyurus, Init differs as follows: 



The facial suture reaches the posterior margin near the genal angle, the anterior 

 end of the glabella overhangs the concave border; glabellar furrows arc eiuirelv ab- 

 sent, and the eyes are somewhat farther forward. The pygidiimi is without concave 

 border, the ribs of the pleural lobes are reduced to nodes, and the axial lobe is ringed 

 for almost its entire length. 



Petiguriis Nero (Billings) an Irish species descril)ed by Reed, 1910, as Btitliyunis aff. 

 ncro. differs in the posterior end of the facial suture, turns sharply outward behind the 

 eye, forming a broad, fixed cheek, different from Petigiirus nero, and from any species 

 of Bathyurus. 



The author also refers to the genus Petigiirus ryhele (Billings). 



Family Solenopleuridae Angelin : 



The author gives the following diagnosis of his new genus Hystricurus: Tvpe Batliy- 

 rus roniciis Billings. 



Glabella conical, tapering towards the front, outlined by deep furrows at sides and 

 front; glabella furrows absent; fixed cheeks long, extending nearly to the genal 

 angle; dorsal furrows paralleled by a nnrrow, roinex ridge; eves of medium size, situ- 

 ated opposite the middle of the glabella ; cranidium with deeply concave border in 

 front; pygidiinn roinuied, with concave border, axial lobe prominent, with 5 rings, 

 and there are 5 pair of ribs on the pleural lobe; surface smooth or pustulose. 



In addition to. the t\ pe which the author illustrates, he includes under the genus 

 Hystricurus crotalifrons (Dwight, 1884) and //. cordai (Billings), B. seelyi Whitf. 

 Bull. Am. Mus., vol. 2, p. 62, pi. 1.1, figs. 8-14, as n synonym, and not B. seelyi, vol. 1, 

 1886, referred to Bolhorcplialus. 



Family Proetidae Barrande: 



Genus Haploconus nov. This genus is proposed to include I'rilobites related to 

 Cyphaspis, but differing in not having isolated basal lobes on the glabella, and in 

 having a less prominent axial lobe on the pygidium. T> pe Batliyrurus smitlii Billings. 



The author describes H. smitlii, and includes in the genus (Cyphaspis .'' galeiwtisis 

 Clarke, and probably C. f bre-vimarginata Walcott. 



Family Dikelocephalidae, Miller, 1889: 



Miller includes in the family Dicellocephalus, Pterocephala and Pt\chas|iis. 



The author jiroposes the new genus Platycolpus, for Bathyurus captix Billings, a 

 Trilobite with hemispheric, rather smooth cephalon, a depressed glabella extending 

 to the anterior border, which is a Hat, striated rim; glabella furrows faint or absent; 

 eyes small, situated midway on the length of the head; facial sutures cutting the pos- 

 terior margin just inside the genal angles, and the anterior margin in front of the eye. 



P>gidium semi-circular, \viihout depressed border and with faint traces of segmen- 

 tation. 



The author describes Platycolpus capax (Billings), P. eatoiii Whitf., which has faint 

 glabella furrows, also P. duhius with a inore pointed glabella, and /'. harahuensis Whitf. 

 with a more convex glabella. 



Family Agraulidae Dalman: 



Cnder the new genus Plethopeltis with Igraulns saratngetisis Walcott, for the t\pe 

 the author gives the following diagnosis: 



Cephalon strongly convex, wider than long, without concave border or marginal 

 rim; glabella faintly defined, without glabella furrows; eyes small, situated well for- 



