Dr. H. Woodward — Garhoniferous Arthropods. 469 



4. Peestwichianella, gen. hoy., 1918. 



Presitvichia, H. Woodw., November 21, 1866. 



P. rotundata, H. Woodw., Quart. Journ. Geol. Soc, vol. xxiii, p. 32, pi. i, 



fig. 2, 1866. 

 Limulus rotundiis, Prestwich, Trans. Geol. Soc, ser. ii, vol. v, pi. xli, 



fig. 5, 1840. 

 Seeing that the name of PresUvichia, H. Woodw., was preoccupied 

 by Lubbock in 1863, I now propose to substitute, for the species 

 P. rottmdata, the new generic name of 



Prestw ichtcmella, H. Woodw., gen. nov.^ 

 Character amended.- — Head-shield semicircular. The genal borders 

 and frontal margin are broad and smooth, and curved roundly on 

 each side towards the thoracetron and ending in moderately broad 

 lateral genal spines ; the glabella is divided along the centre by the 

 axial furrow, and by two other slightly diverging parallel lines on 

 either of the axes, reaching nearly half-way to the frontal border, 

 where they are arcaded, forming a rounded raised confluent line in 

 front of the glabella. The circular line seen outside the border of 

 the glabella may indicate the impression of the line of the broad 

 incurved under-margin of the head-shield. 



The thoracico-abdominal series of segments are apparently united 

 together into one buckler, as seen in the larval stages of living 

 Limulus (see H. Woodward, Mon. Pal. Soc, Merostomata, pt. v, 

 pi. xxxiii, figs. 10-12, 1878). Central axis of body-segments 

 narrow; abdomen rudimentary and coalesced with the hindmost 

 thoracic segment, most probably bearing a short telson or tail spine. 

 The broad membranous margin of the thoracetron extends nearly to 

 the extremities of the seven strongly marked spines. Pive short 

 spines mark the posterior margin of the head-shield, and some small 

 tubercles along the centre of the posterior axis with a more prominent 

 spine near the base of the telson. 



5. Note on Bellinuetts Tkechmanni, a new species of Limuloid 

 Aetheopod from the Ddeham Coal-field. 

 I have been favoured by Mr. C. T. Trechmann, of Castle Eden, 

 Durham, with the loan of a small specimen of a fossil " king-crab", 

 which he lately collected in the highest Coal-measures of the Durham 

 Coal-field at Claxheugli on the Wear, near Sunderland. The beds 

 are in the zone of Anthracomya Phillipsii, not generally known to 

 occur in the Durham area, and as they will be shortly described by 

 Dr. Trechmann he kindly permits me to notice this find in advance. 



In 1866 I communicated a paper to the Geological Society, "On 

 some points in the Structure of the Xiphosura, having reference to 



line and the orbital suture are quite distinct and apart from each other (see 

 Mon. Merostomata, pt. v, pi. xxxiii, fig. 10, after Packard; fig. 12, after 

 Dohrn's " Trilobitenstadiuvi ") . In the adult living Limzdus the compound 

 eyes occupy the lateral border of the glabella. 



^ P. anthrax and P. Birtivelli are now referred to Eup^'oops. 



" See description in H. Woodward's Monograph on the Merostomata, Pal. 

 Soc. vol., 1878, pt. v, pp. 244-7, pi. xxxi, fig. 5. 



