S. II. SCUDDER ON PALAEOZOIC COCKROACHES. 129 



Polyzosterites granosus. 



Adelophthalmus [Eurypterus) granosus Meyer, Palaeontogr., iv, 8-12, pi. 2, figs. 1, 2. 

 Eurypterus granosus Salt.-Woodw., Chart foss. Crust., pi. 3, fig. 15. 



Polyzosterites granosus Gold., Vorw. Faun. Saarbr., 18; — lb., Faun, saraep. foss., i, 18, 

 pi. 1, fig. 17; — lb., Faun, saraep. foss., ii, 20, 51. 



Goldenberg describes the species as follows : — 



" The pronotum, beneath which, as usually, the head lies concealed, is semi-elliptical, nar- 

 rowed and rounded anteriorly; its greatest breadth, which falls near the posterior blunt 

 angles, is scarcely less than 28 mm. ; the length does not appear to have exceeded 16 mm. 

 The convexity is gentle, and the slightly concave posterior border is accompanied by a 

 feeble margin. The next two thoracic segments have in general a shape similar to that of 

 the succeeding segments of the abdomen. All of them are tumid, not only laterally, but 

 also in front and behind, and bordered with a slender marginal piece, connecting each seg- 

 ment with the preceding. The abdominal and thoracic segments together form a regular 

 oval; the pointed, lobe-shaped outer extremities of the segments become gradually larger 

 and broader toward the extremity of the body, as in living species of Polyzosteria ; the 

 last four rings are not so well preserved as the others, and are thrown far out of position, 

 so that the last ventral segment is turned completely around. The thoracic as well as the 

 abdominal segments have the dorsal surface covered with small, crowded tubercles, which 

 are most prominent on the more tumid portions, and by the unaided eye can be seen to be 

 of a blunt, triangular form, directed backward. An entirely similar structure may be seen 

 in what appears to be Polyzosteria limbata Burm. Had such an animal been found fossil, 

 it would very likely have been taken for a Blind Eurypterus, were it not for the form of the 

 extremity of the abdomen, which in all Eurypteri is linear or linear-lancet shaped." 



'"This fossil was found in the Eisenbahnschaeht near Ja>ersfrende. in an ironstone nodule. 



O 



Near Altenwald I found also in such a nodule a similar fossil, but not so completely pre- 

 served, which may probably have belonged to another and smaller species of this genus." 



Goldenberg figures an articulated fragment found beside the abdomen, and which Meyer, 

 considering the animal as a Eurypterus, had compared to the maxillipeds or false abdom- 

 inal feet of the modern genus Serolis, but which Goldenberg takes for a Myriopod, like 

 Polyxenus. So far as his illustration goes, it might be taken for the antennae of the insect 

 itself. The form of the last segment indicates a female. 



J a 



Postscript. November, 1879. — It will not fail of notice how opposed to the drift of 

 this entire essay is the statement of Gerstaecker (Bronn's Klassen und Ordnungen des 

 Thierreichs, v, 292) that the cockroaches described byGermar and Goldenberg from Wettin 

 and Saarbriicken agree in everv distinctive family characteristic wiili those now living 

 (•' stimmen in alien fur die betreffenden Familien charakteristischen Merkmalen mil 

 denjenigen der Jetztzeit ilberein"). in the same place (p. 291) Gerstaecker remarks that 

 scarcely a single extinci form of cockroach approaches in size the largest living species 

 of the family. Yet. as I have state!, the average size of ancient types may be considered 

 somewhat larger than in modern times. 



Gerstaecker (loc. cit. ':'. ; i! note) considers the wing described by Dohrn under the name 

 of Fulgora Ebersi as the hind wing of a cockroach, with most of the anal field destroyed. 



■ ! nisi \ OL. III. 17 



