PALEONTOLOGIC CONTRIBUTIONS I05 



those of Lepidocoleus than to those of any other cirripede genus. 

 Moreover, the reversed symmetry of the plates, while each plate is 

 decidedly unsymmetrical in itself, proves that there must have been 

 double rows of them, exactly as in the Lepidocoleidae. The prin- 

 cipal difference between Lepidocoleus and Anatifopsis consists in 

 the fact that in the former the plates of each column are contiguous 

 or overlapping with their longer side, so that with the overlap the 

 column is buiit up of narrow transverse plates, while in Anatifopsis 

 it is composed of plates which overlap or are contiguous with their 

 narrower sides, so that the column consists of narrow longitudinal 

 plates. We have little doubt that, as in Lepidocoleus, the apexes of 

 the plates were at the ventral side, where the plates were only in 

 contact and there was a dehiscence for the protrusion of the 

 appendages while on the dorsal edge the plates were interlocked. 

 The grooved edge of a plate, as that figured in plate 32, figure 8, 

 distinctly suggests an interlocking along that edge. 



There is some doubt as to the geologic horizon of this species. 

 The specimens were all obtained in the railroad cut north of Otis- 

 ville, on the eastern slope of the Shawangunk mountain, in a horizon 

 which, according to Mr H. C. Ward ell, is above the Eurypterus- 

 bearing beds of the Shawangunk grit and which, according to Mr 

 C. A. Hartnagel, belongs to that portion of the Longwood shales 

 that corresponds to the Binnewater beds of the Kingston region. 



Pseudoniscus roosevelti Clarke 



Plate 33, figures 6 and 7 



The eyes of Pseudoniscus have for some time been an object of 

 speculation. Nieszkowski, 1 who first described a Pseudoniscus, 

 figured a small incision along the edge of the fixed cheek as place 

 for the eye; Eichwald in his Lethaea rossica (i860, p. 1445) speaks 

 there of large lunular eyes, and Woodward in his well-known 

 Monograph of the Merostomata (pt 4, p. 177, fig. 65) restored the 

 head shield completely with the eyes. This figure, which shows 

 eyes half as long as the carapace, has, on the authority of Wood- 

 ward, gone into the textbooks (as Nicholson and Lyddeker, 

 " Manual of Palaeontology," v. I, p. 549, fig. 412, B), although 

 Zittel's Handbuch der Palaeontologie (v. 2, p. 642) does not men- 

 tion the eyes at all. 



1 Zus. z. Monogr. d. Trilob. d. Ostseeprov., in Arch, fur Naturk. Liv. — , 

 Est— und Kurl. I. Ser., Bd. II, p. 381, pi'. II, fig. 15. 1859. 



