I20 ALLEN 



From the previous description it would seem that the vascular 

 system of Anoplopotna exhibits many points of resemblance to 

 the more generalized Teleosts. The external carotid, hyoidean, 

 subclavian, hypobranchial, and coronary trunks appear to have 

 a more primitive arrangement than is even shown in Scbastodcs. 



IX. GENERAL CONSIDERATIONS AND SUMMARY. 



Since it is almost impossible to determine whether certain 

 variations in the blood vessels are primitive or secondary it is 

 not the intention of this paper to draw any conclusions as re- 

 gards the classification of this group on the basis of the circu- 

 latory system, until after the anatomy of the other S3'stems has 

 been worked up. Still it is thought, although perhaps not 

 practicable, that the vascular system might be used in the class- 

 ification of families and genera, but could not be used in the 

 discrimination of species. In the genus Sebastodes a great 

 number of species w^ere studied, both generalized and special- 

 ized, but no more variation was noticed in different species than 

 could be found among individuals of the same species. 



Several interestino: anastomoses were noticed in both the 

 arterial and venous systems. In Ophiodon we have in the re- 

 gion of the nasal sac a union of a branch of the internal carotid 

 with one of the external carotid. The hyoidean artery anas- 

 tomoses with the main stem of the external carotid to form the 

 mandibular artery. A branch of the ventral artery joined one 

 of the subclavian in the pectoral fin canal. The anterior spinal 

 artery, a branch of the subclavian, united in the neural canal 

 with the myelonal artery, a branch of the internal carotid. 

 Two gall-bladder arteries unite on the surface of tlie bladder. 

 Usually the posterior mesenteric artery communicates with in- 

 testinal artery(,), and there are connecting arteries between the 

 right pyloric ca3ca artery and intestinal artery(,,. In Scbastodcs 

 the two anterior spermatic arteries unite with the posterior or 

 spermatic artery projier. In Hexagrammos tlie two hepatic 

 arteries anastomose. In Anoploponia the h3'oidean arteries 

 anastomose with the pseudobranchial arteries, and the hypo- 

 branchial arteries unite with the anterior ventral arter}'. Among 

 the veins in Ophiodon there is an anastomosis under the nasal 



