278 



im 4. Myotora bildend, auf der andern, linken Seite aber, bloß bis zum 

 4. Myotom. Dem ungeübten Beobachter könnte es scheinen, als wäre 

 auf der rechten Seite das Ganglion des 4. Myotoms atrophiert, während 

 es tatsächlich noch gar nicht differenziert ist. 



Über die Visceralmuskulatur folgt in nächster Zeit eine besondere 

 Mitteilung. 



Meine hier angeführten Beobachtungen sind nach vorzüglichen 

 Schnittserien des Zoologischen Kabinetts der Universität in Kasan, die 

 ich dem Student der physiko- mathematischen Fakultät, S.A. Tichenko, 

 verdanke, gemacht worden. 



21. Februar 1906. 



4. An Abnormal Dogfish (Scyllium canicula). 



By Geo. P. Mudge A.R.C. Sc. London, F.Z.S. , Lecturer on Biology at the 



London Hospital Medical College and at the School of Medicine for Women 



(University of London). 



(With 1 fig.) 



eingeg. 18. März 1906. 



The dogfish now described was about to undergo dissection in a 

 class, when the apparent absence of the whole stomach attracted attention. 

 Upon opening the pharynx by cutting laterally through its right and 

 left wall, there was seen lying in its cavity a flattened spathulate-shaped 

 mass (Fig. 1 S') which was at first sight suggestive of the existence of a 

 hernial sac. Subsequent examination of it shewed however that it was 

 not of this nature. Upon cutting open the sac, the distal loop [D) of 

 the siphonal stomach and the spleen {S) were seen contained within it. 

 The posterior end of the sac opened into the abdominal coelom and 

 was lined internally by coelomic epithelium. Through this wide orifice 

 into the abdominal coelom, the distal loop of the stomach passed 

 and was immediately continued into the anterior extremity (bursa 

 enteriana) of the colon (C). Immediately behind this orifice and extend- 

 ing partly into it, was the pancreas (Pj, otherwise normal in its relation- 

 ships, but slightly smaller than usual. The pancreatic duct opened into 

 the bursa enteriana at the normal place. 



The anterior mesenteric artery ran a perfectly normal course, but 

 while the lieno- gastric artery [G] arose from the aorta [A] in its proper 

 position, it ran forwards through the wide coelomic orifice of the sac to 

 its anterior end, where it divided to supply the spleen (S) and a peculiar 

 triangular-shaped caecal invagination (J) of the anterior end of the sac. 

 The lieno-gastric artery is thus very much longer than the normal one, 

 and so much so , that extension of it to this degree would undoubtedly 



