— 73 — 



the lachrymal bone by the single large aperture on the dorso-anterior edge of that bone. The canal 

 then traverses the lachrymal, giving off two primary tubes in its course, these tubes opening on the 

 outer surface by small groups of pores which lie one between the anterior and next posterior spine 

 of the bone, and the other between this latter spine and the next posterior one. The fourth tube of 

 the line leaves the canal as it passes from the lachrymal into the first suborbital, and the fifth tube 

 as it passes from that bone into the second suborbital, these tubes both opening on the outer surface 

 by small groups of pores that lie ventral to the canal. 



In the second suborbital (third infraorbital) the canal runs backward nearly to the bind edge 

 of the bone, where it issues from the bone on its external surface and ends, having given off one 

 primary tube in its course. This latter tube is the 6 th. tube of the line, the canal ending in a terminal 

 tube which represents one half of the 7 th. tube of the line, as will be further explained below. These 

 two tubes lie rather close together, near the hind edge of the bone, the 6th. tube directed postero- 

 ventrally and the 7 th. one postero-dorsally. Both tubes open on the outer surface by a group of 

 pores, and certain pores of the 7 th. group had secondarily fused, in all the several specimens examined, 

 with certain pores of the penidtimate dendritic System of the preopercular canal, a dermal communi- 

 cation between the hind end of the suborbital section of the main infraorbital canal and the preoper- 

 cular canal thus here being established. This communication is large and important, and one not 

 thoroughly conversant with this subject might naturally be led to say, as Garman ('99) has said of 

 Ectreposebastes imus, that the postorbital portion of the main infraorbital canal and the dorsal 

 portion of the preopercular canal were here ,,reduced to a single canal". This however would cert- 

 ainly be, if said of Scorpaena, and must also be of Ectreposebastes, a most misleading statement 

 of the case, for the two main canals themselves do not in any sense here run into each other, a cert- 

 ain pore or pores of a dendritic System of one of them simply anastomosing, secondarily, with a 

 certain pore or pores of a dendritic System of the other. 



Beyond the 7th. primary tube, the main infraorbital canal is interrupted, the next posterior 

 section of the canal being enclosed in the little postorbital ossicle, and not having any direct connection 

 with the suborbital portion of the line. The 7 th. tube of the line is thus the terminal tube of an 

 anterior, suborbital portion of the line, and is the anterior half, only, of what would be the 7th. 

 primary tube of a continuous canal. The other half of this primary tube lies directly behind the eye, 

 at the ventral edge of the little postorbital ossicle, and forms the anterior tube of the postorbital 

 section of the canal. In some specimens the dendritic System formed by the repeated subdivisions 

 of this posterior half of the 7 th. primary tube seemed to be in secondary communication with the 

 penultimate system of the preopercular canal, but, in the one wholly satisfactory preparation 

 made, this connection did not exist. The dissection necessary to establish this is a difficult and 

 delicate one, and the use of injecting fluids is usually misleading, for the delicate walls of the tubes 

 are easily broken down and artificial connections thus established. 



Starting from the posterior half tube of the 7 th. primary system of the line, the canal runs 

 upward through the postorbital ossicle and then traverses the relatively wide interval between this 

 ossicle and the postfrontal bone, there lying immediately beneath the thin dermis. From this part 

 of the canal the 8th. primary system of the line arises, this System being a large and complicated 

 one, and having much more the appearance of two half Systems that have secondarily anastomosed 

 than of two half tubes that have completely fused to form a single tube and system. The branches 

 of this System extend backward across the cheek, and one of them anastomosed, in all of the spec- 



Zoologica. Heft 67. 10 



