28 The Ottawa Naturalist. [May 



Wedekind 9 to get the same standing that Trinucleus has. 



Enough of the destructional phase of the subject. When 

 I wrote before I did not see any way in which the name Tri- 

 nucleus could be retained, but after studying the large collection 

 in the Museum of Comparative Zoology, a way has presented 

 itself. The present tendency is to split our large genera up into 

 a number of smaller groups, and "Trinucleus" must doubtless 

 be so divided. There are at present only two divisions in use, 

 Cryptolithus or Trinucleus, and Tretaspis, McCoy. As stated 

 in my previous paper, Murchison's first species, Trinucleus 

 caractaci, is strictly congeneric with Cryptolithus tessellatus, but 

 fortunately Murchison described six species when first proposing 

 Trinucleus. The fifth of these species, Trinucleus nudus, is 

 well known to be an Ampyx, and the sixth, Trinucleus! asa- 

 phoides, was referred by Salter to Ogygiocaris buchii. This 

 leaves four species, the first and fourth of which, Trinucleus 

 caractaci and T. lloydi, belong to the earlier genus Cryptolithus. 

 The second and third, Trinucleus fimbriatus and T. radiatus,have 

 been referred by Salter 10 to Tretaspis. Now the type of Tretaspis 

 is Trinucleus seticornis, (Hisinger), as that species was under- 

 stood by McCoy 11 . Tretaspis differs from Cryptolithus in having 

 only the anterior part of the glabella bulbous, while the posterior 

 part is constricted and shows two pairs of deep glabellar furrows. 

 The cheeks also show eye-lines and simple eyes are present, even 

 in the adult. Young specimens of some species of Cryptolithus 

 show a poor development of these same characters, but as they 

 are retained in the adult of Tretaspis seticornis, T . bucklandi, 

 and other forms, (Tretaspis reticulatus, Ruedemann is a good 

 American example), the genus is a valuable one, and well found- 

 ed. Trinucleus fimbriatus and T. radiatus do not, however, 

 conform strictly to the type of either Cryptolithus or Tretaspis. 



' Since my previous paper was written, this recent blunder, for such 

 it seems, has come to my attention. Wedekind, in an article on the 

 " Klassifikation der Phacopiden'' in the Zeitschrift der Deutschen Geol. 

 Gessellschaft, Bd. 63, heft 3, p. 323, 1912, has proposed the generic name 

 Glockeria with Phacops glockeri as the type. Reed, as recently as 1905, 

 on page 226 of the Geological Magazine of that year, proposed the name 

 Phacopidella with Phacops glockeri as the type. Wedekind refers fre- 

 quently to Reed's paper, and quotes Phacopidella, though he nowhere 

 says that that name is preoccupied or otherwise unusable. Wedekind's 

 Glockeria is not the same as Reed's Phacopidella, but it seems obvious 

 that we can not found two genera upon a single species. I regret to have 

 to add that the name Reedia was used by Ashmead in 1904 for a genus of 

 wasps (Canadian Entomologist. 36, p. 9), so that Wedekind's intended 

 compliment to Professor Reed is lost. In passing, it might be noted that 

 Phacops fecimdus Barrande, is not the type of Phacops s. s. as Wedekind 

 has made it. 



,0 Mem. Geol. Sur. Unit. Kingdom, Dec. 7, p. 8, 1853. 



"Ann. Mag. Nat. Hist., ser. 2, vol. 4, pp. 401, 410, 1849. 



