30 SAN DIEGO SOCIETY OF NATURAL HISTORY 
ETHERIDGE (Robert, Jr.) and MITCHELL (John)—Continued 
The authors describe: 
Odontopleura Bowningensis n. sp., O. Rattei n. sp., O. parvissina n. sp., O. Jenkinsi 
n. sp., (The Acidaspis Brightii Jenkins mon. Murchison). Ceratocephala Vogdesi n. sp. 
(Acidaspis Verneuili Ratte non. Barrande), C. Jackii n. sp., C. impedita n. sp., C. long- 
ispina Mitchell. 
—— The Silurian Trilobites of New South Wales with references 
to those of other parts 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: 
Encrinurus Mitchelli Foerste, referring Cromus Murchisoni DeKoninck, pl. 1, fig. 9 
(exclude figs. 9a and 9b) to the species. 
Encrinurus Bowningensis Foerste. 
The following are described as new species: 
Encrinurus silverdalensis, a robust species, about 2 inches long; the head approaches 
E. variolarlis, but its enormous tail separates it from the European species. 
Encrinurus Etheridget, the largest Australian form known, has a length of 2% 
inches, of which the tail occupies one inch. 
Encrinurus Rothwellae. 
The subrectangular and steep-sided thorax, very prominent thorax and pygidial axis, 
a circular end of the tail—axis, 11 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. Mitchelli. 
Encrinurus 2 duntroonensis. 
The authors illustrate only the head, which differs from all other species referred to 
Encrinurus. 
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 the 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 anteriorly situated free cheek. 
5. The sparse tuberlation. 
6. The backward and inward situation of the eyes. 
7. The manner in which the axial furrows bifurcate outward and inward on reach- 
ing the frontal borders of the free cheeks. 
The authors suggest a new genus without naming it. Why not that of Mitchellia 
after this well-known author on the fossil Crustacea. 
Fearnsides (W. G.), Elles (G. L.) and Smith (Bernard). The Lower 
Paleozoic Rocks of Pomeroy. 
Proc. Royal Irish Acad., vol. 26, sec. B, No. 9, 1907, pp. 97-128, map and plate. 
Trilobites: Trinucleus concentricus Eaton; also var. Portlockiit Salter and yar. elon- 
gatus Portl. and var. arcuatus. 
Trinucleus seticornis His. Dionide cfr. euglyptus Ang. A glina rediviva Barr. 
Phacops mucronatus Brong. 
The other Trilobites collected from Pomeroy have been described by Portlock in his 
Londonderry report. 
Field (R. M.) Use of the Roentgen Ray in Paleontology Skiagraphy 
of Fossils. 
Am. Jour. Sci., vol. 39, 1915, p. 543. 
