Subcutaneous Vessels in Tail of Lepisosteus 61 



Lateral Subcutaneous Ti-unks. — Unquestionably these subcutaneous 

 trunks have received far more attention than any of the others. 



With the Selachians, Parker {op. cit., p. 721) observed that the 

 lateral cutaneous vein in Mustelus anastomoses posteriorly with both 

 the dorsal cutaneous and the caudal veins. Sappey (op. cit., p. 38) 

 found two lateral lymphatic trunks in Squalus. Le tronc lateral 

 superieur (PI. X, Pig. Ill, 2) is represented as running along parallel 

 with the mucous canal; caudad it expands into a fibrous caudal sinus, 

 which opens into the caudal vein. Le tronc lateral inferieur (PI. X, 

 Pig. Ill, 11) is portrayed as traveling along the median lateral line, 

 parallel to the lateral line, but more superficially. Posteriorly this 

 trunk is indicated as gradually rising higher and higher until it eventu- 

 ally anastomoses with the superior lateral trunk. Sometimes (evidently 

 meaning in some species) Sappey notes that the inferior lateral trunk 

 is absent. Certain cross vessels (Fig. Ill, 14, 12 and 3) connect the 

 ventral trunk with the inferior lateral, the inferior lateral with tha 

 superior lateral, and the superior lateral with the dorsal, and the cross 

 vessels drain a subcutaneous network (13). Mayer {op. cit., pp. 316-7, 

 and PI. 16, Figs. 2-4, v. I.) describes the vena lateralis as receiving the 

 vena dorsalis and anastomosing with the vena ventralis, which has 

 already been cited as emptying into the vena caudalis. In a footnote 

 on p. 317, Mayer states that in a section through an injected specimen 

 of 8. canicula he saw a minute connection between the lateral and the 

 caudal veins. This communication is recorded as l3eing caudad of the 

 anastomosis of the laterals with the ventral. 



Hyrtl {op. cit., p. 233 and Fig. 7) represents the lateral lymphatic 

 in various Teleosts as collecting numerous paired cross vessels, which 

 receive a superficial network. On pp. 234-5, he states that each lateral 

 trunk terminates in a caudal sinus (PL X, Figs. 1, 2 and 4, a) imme- 

 diately behind the last vertebra. A longitudinal neural and a h^mal 

 trunk culminate in one of these sinuses, and both of these sinuses empty 

 into the caudal vein. Besides terminating in a caudal sinus, each 

 lateral trunk in Salmo is described by Vogi^" (pp. 135-6 and PI. K, 

 Figs. 3-5, 66) as continuing to the base of the tail, where it separates 

 into a dorsal and a ventral sinus, each of which communicates on the 

 opposite side with a similar sinus. Both of the caudal sinuses open 

 into the caudal vein and the orifice is said to be guarded by a valve. 



^"Vogt, C. "Anatomie des Salomes." Memoires de la societe des sciences 

 naturellcs dc Xetichatel. 1846. 



