PTEROPODA. 5 



(B.) Whitish specimens. In these the prevalent coloration is white or grey, 

 the black visceral mass being seen more or less distinctly, according to the 

 transparency of the shell. The animals are not much expanded, the fins being 

 usually retracted, but the shells are better preserved than in the black and yellow 

 specimens, being thicker, more opaque, less broken and less perforated. The breadth 

 is about 3 mm. and the height about I 1 75. These specimens were probably put 

 straight into alcohol, which accounts for the contracted state of the soft parts and 

 good preservation of the shell. They are recorded from : 



(1) W. Q. ..... Fairly numerous. 



(2) McMurclo Bay . . . .A few. 



(C.) These specimens, which are extremely numerous, are distinguished by 

 (a) their small size, the diameter being usually about 1'50 mm., and few whorls; 

 and (b) the position of the fins, which form a sort of hood extending beyond the 

 anterior part of the body. As this hood often bears fragments of shell, the whole 

 animal sometimes bears a resemblance to Limacina inflata, as figured by Souleyet. 

 But a comparison with specimens of that form, kindly lent me by Mr. E. A. Smith, l.s.o., 

 shows that the resemblance is merely superficial, and that there is no true rostrum 

 above the hood. The coloration is varying : pure yellow, black and yellow, white, 

 grey, and dark grey being all found. Some of the animals have been treated with 

 picric acid, and some apparently put straight into alcohol or formol. The majority 

 of the shells are poorly preserved, though in so large a mass of material good 

 specimens were not wanting. An operculum is generally present ; otherwise this 

 form resembles those described above as A and B. and may be regarded as a 

 younger stage. 



The Expedition brought back twenty-three tubes containing specimens of this 

 type, all captured at Winter Quarters, none being recorded from elsewhere. 



Taking all the specimens together, I have little doubt that they represent a 

 single species which may be thus described. 



The shell is between 5 and 6 mm. broad in large individuals, but considerably 

 smaller in the majority, and the height is about half the breadth or rather less. In 

 the best specimens it is white, imperfectly transparent, and faintly but distinctly 

 striated, but the action of the preserving fluid often renders it extremely fragile 

 and the stria tion may disappear. There are 3-6 whorls (5-6 in large specimens) 

 divided by distinct sutures. The last whorl is considerably dilated and terminates 

 in a large rounded lip, which is generally broken. The spire is somewhat flattened. 

 The umbilicus is moderately wide and deep, but is not surrounded by any raised keel 

 or special border. 



In large specimens the fins (fig. ib) are about 4 mm. long and 3 mm. broad 

 across the tips. They are shaped much as in L. lu'lici/ia and bear a small accessory 

 lobe. The right tentacle is well developed, the left rudimentary. The foot is ample 



