ADDENDA 6. SCYLLIID^ SCYLLIORHINUS. 869 
Page 11. Instead of P. nigricans Le Sueur, read: 
12. P. mai’iaiiis, subsp. dorsatus Wikler, sp. nov. 
The ^^Fetromyzon nigricans^^ of the Atlantic coast streams seems to 
be the young of P. marinns. The Cayuga Lake Lamprey described in 
the text on page 11 is apparently a distinct subspecies, differing from 
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) ; maudibulary teeth usually 8 or 9. Males iciih the hade before 
dorsal fin compressed in a long, hard, fiesliy ridge. Interspace between 
dorsals variable in length, shortest in males, i to f base of first. 
Tail 3f in length. Coloration of P. marinus, and size not much less. 
Abundant in Cayuga Lake, Js^ew York; not yet observed elsewhere. 
The differences above noted are not very constant. 
(Wilder MSS. : Petromyzon nUjricans J. & G., pa,<;e 11 of this work. ) 
Page 14. Under Fchinorhinus the reference 
(Blainville, Bull. Scl. Pbilomatb. 1816, 121) 
should be snpidied. 
Page 18 (and 59). Instead of genus 13 {h) Scyllium Cuvier read: 
13 (&).— SCYI.LIORIIII^US Blainville. 
(Blainville, Bull. Sci. Philom. 1816, 121 : type SeyUiorliinus catulus Blainville = 
canicuIa L.) 
The generic diagnosis of Scyllium, on page 59, applies to Scyllio- 
rhinus, with the exception of the danse “nostrils separated by a broad 
isthmus”, which is true of part of the species (snbgeuns Catulus Smith) 
only. Species 18 {h) should be “;S'. ventriosus (Garniau) J. «& G.” 
After 18 [h), 8. ventriosus, add: 
18 (c). S. retifer (Garmau) 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 month 
less than distance between outer margins of nostrils; nasal valves 
broader than isthmus between them, not reaching month, 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- 
