21 EINAR LÖNNBERG: NOTES ON SPIRULA RETICULATA OW] 117 



something more than merely the slits ("Schlitze" Appellöf, in Veranya, CkaunoUu- 

 lias; "Spalter", Posselt, in Todarodes 1 ; "Schlitzförmig", Brock in Ommatostrepkes 

 (I. c.) etc.) of the OEgopsids and cannot confirm Spirit/as affinity with these latter 

 animals, - more likely the contrary, for we know that in son* Sepia the renal 

 papillae are very small \ 



In describing the circulatory system of Spirula Pelseneer writ 

 (p. 23): "The short posterior aorta gives off immediately tu the hit a recurrent 

 branch ("anterior" aorta), which supplies the rectum and in part .it least the genital 

 organs." This "recurrent branch" Pelseneer regards as the homologue of the arteria 

 genitalis, and as that vessel arises directly from the ventricle in the Myopsids, but 

 branches off from the recurrent branch ("anterior aorta" Brock) from the posterior 

 aorta in the OEgopsids, he supposes the situation of this vessel to be a chara 

 which approaches Spirula to the OEgopsids. It seems to me however questionable, 

 whether this "recurrent branch" in Spirula is homologous to the arteria genitalis. 

 It "supplies the rectum and at least in part the genital organs" and thus at any rate 

 corresponds not only to the arteria genitalis but also to the other branches 1 of the 

 "aorta anterior" (Brock) of the OEgopsids. In some Myopsids (e. g. Inioteuthis mor- 

 sa) there is ' a special arteria genitalis from the ventricle, as usual in these forms, 

 and a "recurrent branch" ("anterior aorta") from the posterior aorta supplies the rec- 

 tum, the ink bag and vas deferens, thus "in part the genital organs". Might not 

 now the "recurrent branch" of Inioteuthis and that of Spirula be homologous, and 

 in the latter the true arteria genitalis arise somewhere else? The descriptions given 

 by Owen and Pelseneer are not detailed enough to satisfactorily answer this q 

 tion. The arteria genitalis has a very different situation in different forms, some- 

 times even when they belong to related groups, for instance in Chaunoteuthis it 

 branch 6 from aorta cephalica, arising near the ventricle, but in Onychoteuthis it 1 

 in other OEgopsids. Great confusion thus prevails concerning the homology ol the 

 arteries in the Cephalopods, and till this matter is cleared up it is misleading to use 

 characters from the circulatory system to prove the affinity of different forms. 



1 Posselt: Todarodcs sagittatus (Link) Stenstrui\ Vidensk. Meddel. naturh. Foren. Kjobe 

 havn 1890. 



-' It is also to be observed, that although the typical OEgopsids do not have renal 

 papillae occur in Thysanotculhis, Histioteuthis and Chiroteuthis and I have seen such papi 

 gotatthis, but on the other hand the Myopsid Sepiottuthis has "einfache schlitzförmige Öffnungen" (Bro 

 Morph. Jahrb. lid. 6, 1880). 



3 Cf. Posselt 1. c. p. 20. 



1 According to Appellöf: lap. Ceph. 



5 But there are branches from aorta posterior which supply the "Eileiter und I 



Aitellok Teuthol. Beitrage II p. 15. 



