MOLLUSCA HETEROPODA. 421 



Rossia (in the text it is Sepiola, but corrected by the author) dispar is 

 distinguished by the four acetabula of the ten-times longer lateral arms ; 

 each arm has 15 20 acetabula. 



Loliffopsis vermicularis is characterized by the length of the neck ; the 

 anterior margin is equally remote from the eyes and from the commence- 

 ment of the cordate, posteriorly acuminated fin. 



The genus Octopoteuthis\\n\i&$ the characters of the genera Octopus, Lollgo, 

 and Enoploteuthis. The mouth is surrounded by eight arms of equal length, 

 which are furnished with two longitudinal rows of minute hooks ; the vis- 

 ceral sac is conical, iiifundibuliform, contains a very thin horny lamella, and 

 supports on the back, for two thirds of its length towards the apex, a large 

 sub-cordate fin. The species 0. sicula is rose coloured, clear as glass, with 

 red points to the arms. 



Sepia miens, Philippi. (Euum. p. 293). Corpore depressiusculo, utriuque 

 Isevi, rubente ; brachiis pedunculatis prselongis ; lamina dorsali elongato- 

 elliptica, rosea. Naples. 



PTEROPODA. 



Aug. Krohn described in these Arcliiv. (1814, i, p. 

 324} a new pteropodous species, Tiedemannia creniptera. 

 but afterwards communicated, in a letter to the Reporter, 

 the remark, that he had recognised this animal in ForskaPs 

 Descriptiones Animalium, &c., tab. 43, fig. D. The project- 

 ing rostrum, he says, and the characteristic digitiform 

 lobes on the lateral margins of the great fin are distinctly 

 shown. In the text the description of the animal is wanting ; 

 in the explanation of the plate referred to it is called 

 Gleba cordata. With respect to this species, as well as to 

 the Physophoridan afterwards known as Hippopodius luteus 

 (Gleba hippopus, Forsk. ejusd. tab., Fig. E), the editor, the 

 illustrious Niebuhr, also adds, " auimalculo non descripto, 

 sed modo delineate hisque nomiuibus iusignito tradidit, &c., 

 Forsk. Color aqueus et substantia gelatiuosa." 



HETEROPODA. 



On the genus Sagltta, Quoy and Gaimard, respecting 

 which our previous knowledge was very incomplete, we 

 derive very important information from two papers by 



