320 report — 1865. 



the anterior with very fine striae crossed at the margins by equally fine radii. 

 The fine pores between, but not on the coarse ridges, are wanted on the 

 anterior surface. The scale seems to belong to some large Glyptodipterine, 

 and merits description from its occurrence in the same shales with the tooth 

 last described. 



The large transversely oval scale, named Dendroptych'ms, belongs to the 

 same groiip ; its anterior half is finely tubercular by the intersection of con- 

 centric and radial stria? ; the distant, rudely parallel, vermicular, frequently 

 bifurcated ridges of the posterior do not radiate from a centre, but pass from 

 the whole transverse diameter. The determination of this, like the preceding 

 from the same locality, awaits further discoveries. 



The Acanthodian remains are abundant and well preserved. 



Scales of two species of Gyrolepis occur along with those of Palceoniscus. 

 Amblypterus is represented by a few scales. 



The Plagiostomous remains are numerous and varied ; among them occur 

 Orodus, Helodas, Cladodus, and Ctenodus. Among them, as among the 

 numerous spines, are several forms which are yet under investigation. 



Of the genus Platysomus, one species, P.parvulus, and a variety unnamed, 

 are found; the scale ornament of the one is tubercular*, of the other striated. 

 P. striatus, obtained in Berbyshire, is wanting in this coal-field. 



The list both of genera and species will doubtless be augmented when the 

 large mass of materials, collected by Mr. Molyneux and others, shall have 

 been more fully investigated. 



First Report on the Structure and Classification of the Fossil 

 Crustacea. By Henry Woodward, F.G.S. 



A grant having been made in September last at Bath (1864) in aid of my 

 researches into the structure and classification of the Fossil Crustacea, for 

 which the Earl of Enniskillen, Professor Phillips, and Mr. C. Spence Bate 

 were appointed a Committee, I beg to submit my first Beport. 



The first portion of my investigation relates to the Crustacea of the Devo- 

 nian and Upper Silurian formations belonging to the order Eurypterida. 



These are now elaborated, and will be published in a Monograph, with 

 plates . and woodcuts of all the species, by the Paheontographical Society 

 during the ensuing year. 



The following is an abridged list of the genera : — 



1. Eurypterus 9 species examined. 



2. Pterygotus 10 „ ,, 



3. Slimonia 3 „ ,, 



4. Stylonurus 6 „ „ 



5. Herniaspis 5 ? 1 „ 



and includes three genera defined, viz. : — 



JSlimoniaf, Stylonurusi, and Hemias2)is§ ; and also six new species added 



* Anew genus, Amphicentrum, has been founded by the writer upon certain fossils bearing 

 certain strong anatomical resemblances to Platysomus, wliile the dentition indicates affinities 

 with the Pycnodonts. The description of this genus, with a review of its relations, will 

 shortly appear elsewhere. 



t See Intellectual Observer, vol. iv. 1863, p. 229, " On the Seraphim and its Allies." 

 j See Geological Magazine, vol. i. 1864, p. 196, " New Paleozoic Crustacea." 

 § See Quart. Joum. Geol. Soc, vol. sxi. pt, 4, Nov. 1865, " On Herniaspis." 



