Mr W. E. IToyle on Loligopsis and some other Genera. 323 



Taonius cymoetypus (de Eocliebrune), milii. 

 1S39. Loligopsis pavo (pars), d'Orb., Cepli. Acet, p. 321, pi. vi., fig. 4 (?) ; 



pi. xxiii., figs. 10, 11. 

 1884. Phasmatopsis cymoetypus, Rochebr., Monogr. Loligopsidse, p. 17 (9). 



Malacologists are indebted to Dr de Rochebrune for point- 

 ing out the distinctness of this interesting form from T. pavo 

 (Les.), with which d'Orbigny had confused it, and for correcting 

 several mistakes which had arisen in consequence in that 

 author's great work. It is to be regretted, however, that de 

 Rochebrune has fallen into an error which has led him to 

 erect this species into a new genus. 



His description and figure alike indicate the tentacles as 

 present and similar to the sessile arms. A careful examina- 

 tion, however, of the specimen has shown me that the two 

 ventral arms only are complete, and adjoining each of these 

 is the stump of a tentacle, concerning the perfect form of 

 which nothing can be made out; the remaining arms are 

 present, but their tips are wanting. 



In the structure and arrangement of the head and mantle, 

 it does not differ from the typical arrangement in Taonius. 

 The funnel contains no valve, nor is it possible to determine 

 whether an apparatus, such as Verrill has described in his 

 Desmoteuthis, was originally present. 



The ventral arms only are intact, but they are somewhat 

 stouter than any of the others. They are armed with two 

 rows of suckers, alternating with each other, which have the 

 same general structure as in Taonius hyperboreus or T pavo, 

 but differ in details. The innermost are hemispherical, w^ith 

 a small horny ring notched into square teeth ; those from the 

 middle of the arm are larger, but still have square teeth ; 

 while those three-fourths along the arm and beyond gTadually 

 diminish in size towards the tip, and have the horny ring 

 divided into four conspicuous teeth on the distal side. 



The suckers, which are figured by d'Orbigny as of Loligopsis 

 pavo, are in reality those of this form; for those of the 

 original specimen of Taonius {Loligopsis) pavo are all pro- 

 vided with square teeth. The suckers figured by de Eoche- 

 brune as tentacular are taken from these sessile arms, for, as 

 above mentioned, the tentacles are absent. I did not observe 



VOL. VJII. X 



