192 Records of Dredging. 



ceolate white tentacula, which, when the animal is at rest, 

 are reflexed on the shell, along with the edge of the hood. 

 .The shell varies in wanting one of the white bands, which are 

 described as encircling it spirally. 



It will be seen from these descriptions that our British 

 Naticae differ materially, in regard to the inhabitants of the 

 shells, from the generic characters of Lamarck and Rang, 

 who describe the animal as furnished with two tentacula, very 

 long and sharp, bearing on their outer sides sessile eyes. 



In the seventeenth volume of the Linncean Transactions is 

 an important paper by that most observant naturalist, Lans- 

 down Guilding, on the family " Naticidee Guild." in which 

 he divides the Lamarckian genus Natica into two ; namely, 

 Natica and Naticina, characterising the latter from the N. 

 mammilla, and some other West Indian species, the animals 

 of which he found eyeless, and differing from the animal of 

 Lamarck in many other particulars, corresponding nearly 

 with the descriptions I have given above, which were drawn 

 up before I had seen his paper. He, however, describes 

 the mouth as " subtus cartilagineum, proboscidiforme, intra 

 caput retractilium." [Cartilaginous beneath, proboscis-shaped, 

 retractile into the head.] May he not have mistaken the 

 small foot-like process beneath the head for a proboscis, to 

 which it has, indeed, a great resemblance ? 



It would be very desirable to ascertain whether all the 

 Naticidae with corneous opercula are blind, and whether all 

 those with testaceous opercula accord with the descriptions 

 of Lamarck and Rang. 



Should my observation on the tentacula in this genus prove 

 correct, it might induce us to ask the physiological question, 

 Does the absence of eyes degrade the number of tentacula 

 from a generic to a specific character? 



I have my doubts as to the identity with N. monilifera of 

 what are placed as large British specimens of that species : 

 they appear to me more nearly allied to N. rufa. An exa- 

 mination of the animal would settle that point. I have never 

 obtained these shells when dredging : they are said to occur 

 buried in the sand, at very low tides, in the Frith of Forth. 



The N. nitida of Donovan is generally described as being 

 white : my specimens have all brownish bands on a white 

 ground. It appears to inhabit shallower water than either 

 N. monilifera or rufa, and my friend Dr. Knapp informs me 

 it is not uncommon at St. Andrews. I have not as yet seen 

 the animal. 



The N. pallidula and lacuna of Fleming form the genus 

 Lacuna of Turton ; which may constitute a very excellent 



