30 SAN DIEGO SOCIETY OP NATURAL HISTORY 



ETHERIDGE (Rob ert, Jr.) and MITCH ELL (John) — Continue d 



The authors describe : 



Odontopleura Boivningensis ii. sp., (). Ratici n. sp., O. par-vissiria n. sp., O. Jenkinsi 

 n. sp., (The Acidaspis lirig/itii Jenkins mm. Murchison). Ceratocephala I'ogdesi n. sp. 

 (Acidnspls I'erneiiili Ratte non. Barrnnde), C. Jockii n. sp., C. impedila n. sp., (7. long- 

 ispiiia .Mitchell. 



The Silurian Trilobites of New South Wales witli references 



to those of other jiarts of Australia. 



Proceedings Linn. Soc. N. S. Wales, 1915, vol. 40, part 4, 1916. 



Part V, The Encrinuridae, plates 54-57, pp. 646-680. 



The authors describe and illustrate the following species: 



Encrinurns MltclicIIi Foerste, referring Cromus Mtircliisoni DeKoninck, pi. 1, fig. 9 

 (exclude figs. 9a and 9b) to the species. 



Eticr'tnurus Boivningensis Foerste. ' 



The following are described as new species: 



Encrinurns silverdalensis, a robust species, abfiut 2 inches long; the head approaches 

 E. I'ariolarlis, but its enormous tail separates it from the European species. 



Enrrlnurus Etiieridgei, the largest Australian form known, has a length of 2^2 

 inches, of which tlie tail occupies one inch. 



Encrinurns RotliivcUac. 



Tlie subrectangular and steep-sided thorax, very prominent thorax and pygidial axis, 

 a circular end of the tail — axis, II pleural segments in the pygidium, widely expanded 

 and tumid glabella, anteriorly forward eye-lobes, and strong drooping of the pygidium 

 posteriorly, separate this species from E. Mitc/iclli. 



Encrinurns ? duntroonensis. 



The authors illustrate only the head, which differs from all other species referred to 

 Encrinurns. 



1. In the transversely elongated elliptical form of the cephalon, with its nearly 

 straight anterior border. 



2. The closeness of the anterior branches of the facial sutures and tlie perpendicu- 

 larity of the posterior branches of these, with the axial furrows, or central axial line. 



3. The long, narrow and straight-sided glabella. 



4. The anterior!}' situated free cheek. 



5. The sparse tuberlation. 



6. The backward and invvard sitviatinn of tlie eyes. 



7. The manner in which tlie axial furrows bifurcate outward and inward on reach- 

 ing the frontal borilers of the free clieeks. 



The authors suggest a new genus without naming it. Why not that of MitclicUia 

 after this well-known author on the fossil Crustacea. 



Fearnsides (W. G.). Elles (G. L.) and Smith (Bernard). The Lower 

 Pala^ozoie Rocks of Pomeroy. 



Proc. Royal Irish Acad., vol. 26, sec. B, No. 9, 1907, pp. 97-128, map and plate. 



Trilobites: Trinucleus conccntricus Eaton; also var. Portlnckii Salter and var. don- 

 ga t us Port!, and var. arcuatus. 



Trinucleus seticornis His. Dinnide cfr. cuglyptus Ang. .ILglina rcdiviva Barr. 

 Phacops rnucronaius Brong. 



The other Trilobites collected from Pomeroy ha\e been ilescribed by Portlock in his 

 Londonderry report. 



Field (R. ^1.) Use of the Roentgen Ray in I'aheontology Skiagraphy 

 of Fossils. 



Am. Jour. Sci., vol. 39, 1915, p. 543. 



