182 CATALOG OF FOSSIL FISHES IN THE MUSEUM 



oniscid genus, Rhadinichthys. They have been described as three 

 distinct species: 



1. Rhadinichthys devonicus. — J. M. Clarke; Bull. i6, U. S. Geol. 

 Surv., p. 41, Plate i, figures 2-6, [as PalcBoniscum]. 1885. 



2. Rhadinichthys antiquus. — H. U. Williams; Bull. Buffalo Soc. 

 Nat. Sci., V, p. 84, figure 2. [as Palcsoniscum]. 1886. 



3. Rhadinichthys reticulatus. — H. U. Williams; Ibid., p. 86, 

 figure I. 1886. 



Of these three names the last seems to be a synonym of the first; 

 so that only two species may properly be recognized, distinguished 

 from each other by details of ornamentation of the scales and cranial 

 plates. 



Rhadinichthys devonicus (Clarke) 

 (Pis. 59, 60, 61, 62; 63, figs. I, 2; 65; text-figs. 60, 61) 



In 1885 John M. Clarke described an imperfect fish and a number of 

 isolated scales and cranial plates under the name of Palceoniscum 

 devonicum. The specimens were collected in a "railroad cutting 

 through the bituminous layers in the town of Sparta" — a Portage 

 horizon. In the following year H. U. Williams described and figured 

 a number of isolated scales and cranial elements from the Portage 

 near Buffalo, which he placed in two new species, Palceoniscum reticu- 

 latus and P. antiquus. It seems to us on careful comparison of his 

 figures of P. reticulatus with the figures and description given by 

 Clarke of P. devonicus, that these names refer to the same species. 



The following is Dr. Clarke's account of this species: 



One individual retains most of the body in place, though the bones of the 

 head have been displaced and scattered, and the tail is somewhat crushed. The 

 animal was originally about 13 cm. in length. The cranial bones, .... are 

 characteristically marked by punctate incised lines which run along the greatest 

 diameter of the bone, occasionally [as in his figure 5] radiating from the most 



convex portion of the plate Associated with these bones are many 



minute, shining, somewhat flattened, conical teeth, measuring 0.75 mm. in length. 

 The scales, except those on the dorsal ridge, are 1.5 mm. long and 5 mm. wide, 

 subrhomboidal in outline and very beautifully sculptured with strong elevated 

 striae, which take their origin at the upper forward angle and pass obliquely 

 across the scale, the forward edge presenting the appearance of being strongly 

 tucked. These elevated striae become very much stronger at the posterior edge,' 

 and in this region, the upper portion of the scale being left free of striae, shows 

 strong punctate markings. These pittings are also to be seen in the furrows 

 between the striae on the anterior portions of the scale. 



