ADDENDA 6. SCYLLIIDJE SCYLLIOKHJNUS. 869 



Page 11. Instead of P. nigricans Le Sueur, read: 

 12. P. mariims, subsp. dorsatus Wilder, sp. nov. 



The " Petromyzon nigricans" of the Atlantic coast streams seems to 

 be the young of P. marinus. The Cayuga Lake Lamprey described in 

 the text oil page 11 is apparently a distinct subspecies, differing fro?n 

 P. marinus in the longer head (snout 1^ in chest; head half longer 

 than chest; in P. marinus snout If in chest; head one-third longer than 

 chest) ; mandibulary teeth usually 8 or 9. Males with the bade before 

 dorsal fin compressed in a long, hard, fleshy ridge. Interspace between 

 dorsals variable in length, shortest in males, J to -f- base of first. 

 Tail 3| in length. Coloration of P. marinus, and size not much less. 

 Abundant in Cayuga Lake, New York; not yet observed elsewhere. 

 The differences above noted are not very constant. 



(Wilder MSS. : Petromyzon nigricans J. & G., page 11 of this work. ) 



Page 14. Under Echinorhinus the reference 

 (Blainville, Bull. Sci. Philomath. 1816, 121) 

 should be supplied. 



Page 18 (and 59). Instead of genus 13 (b] Scyllium Cuvier read: 

 13 (&). SCYLL,IORHINtJS Blainville. 



(Blaiuville, Bull. Sci. Philorn. 1816, 121 : type Seylliorhinus catulns Blainville = Squalus 

 canicula L.) 



The generic diagnosis of u Scyllium^ on page 59, applies to Seyllio- 

 rhinus, with the exception of the clause "nostrils separated by a broad 

 isthmus", which is true of part of the species (subgenus Catulus Smith) 

 only. Species 18 (b) should be "$. ventriosus (Garman) J. & G." 



After 18 (6), 8. ventriosus, add: 

 1 (c). S. retifer (Garman) J. & G. 



Light brownish, crossed at irregular intervals by groups of 2 to 4 

 narrow black lines, which are joined by other lines, forming a network 

 of polygonal meshes ; belly uniform yellowish. Body moderately elon- 

 gate, the vent in front of its middle. Head depressed, its width nearly 

 equal to its length in front of spiracles; length of snout from mouth 

 less than distance between outer margins of nostrils; nasal valves 

 broader than isthmus between them, not reaching mouth, without 

 free cirrus; length of arch of mouth a little more than half its width; 

 lower labial fold reaching one-fourth distance to symphysis; teeth 

 small, each with a central cusp and two small ones on each side. Pec- 



