EOLIS. 



consider it a northern form, but our knowledge of foreign species is much too limited to 

 allow of our pointing out their geographical distribution with any degree of certainty. 



The body of Bolls is limaciform, in some species rather depressed and ovate, but more 

 generally slender, and nearly linear when extended. The back is rounded, and has no 

 vestige of cloak : the skin is thin and smooth, without spicula. The head is terminal, and 

 scarcely distinct from the body, into which it passes imperceptibly : it is provided with four 

 linear non-retractile tentacles, of which two are dorsal and two labial or oral. The dorsal 

 tentacles are frequently ringed or wrinkled, rarely laminated, but in the greater number of 

 species they are smooth, and only slightly wrinkled when contracted. The eyes are placed 

 behind them. The oral tentacles are always simple, arising either from the margin of 

 the lip or a little above it. A third pair of tentacles is mentioned by Cuvier, but these 

 are merely the elongated margins of the foot. The mouth is sub-inferior, and provided with 

 strong corneous jaws. The branchiae are elongated, cylindrical, ovate or flattened processes, 

 usually called papillae, arranged in transverse rows on each side of the back, and leaving a 

 -naked space more or less visible down the centre : these rows are in some species grouped 

 into clusters. The foot is usually nearly linear, and grooved in front, the anterior angles 

 being in some species produced into long tentacular processes, which may occasionally be 

 used as feelers, but analogy forbids our considering them as true tentacles. They probably 

 assist progression. The aperture of the generative organs is placed forwards on the right 

 side, and the anus is a little behind and above on the same side, generally near or between 

 the branchiae : it is very inconspicuous, and escaped the observation of Cuvier, who states 

 that this and the generative organs are united in one common orifice. 



The members of this genus are all carnivorous, feeding on zoophytes and other small 

 marine animals. Some of them are very voracious. 



The genus may be divided into four sections, characterized as follows : 



Sec. 1. Branchial papilla numerous, depressed, and imbricated. Eolis proper. Type, E.papillosa. 



In this section the body is rather broad and ovate ; both pairs of tentacles shortish and 

 smooth ; and the sides of the foot a little produced and pointed. 

 Spawn consisting of numerous much-waved coils. 

 Sec. 2. Branchial papilla clustered. Flabellina, Cuvier. Type, E. coronata. 



The body is slender and rounded above ; the dorsal tentacles generally ringed or wrinkled ; 

 the oral tentacles long ; and the sides of the foot produced into linear processes. 

 Spawn consisting of many coils, sometimes waved. 

 This section may be divided into three sub-sections. 



* Dorsal tentacles ringed or laminated. Type, E. coronata. 



* * Dorsal tentacles wrinkled or smooth. Type, E. gracilis. 



* * * Dorsal tentacles bulbed. Type, E. alba. 



Sec. 3. Branchial papillce in transverse, generally rather distant, rows. Cavolina, Bruguiere. Type, 

 E. cingulata. 



The body is a little broader than in the last section ; the dorsal tentacles smooth or 

 wrinkled; the oral tentacles shortish; and the sides of the foot slightly produced and 

 rounded. 



Spawn consisting of one or, at most, two coils. 



This section also contains three sub-sections. 



* Papillae sub-linear, rows rather close. Type, E. concinna. 



* * Papillse sub-linear or slightly inflated, rows distant. Type, E. cingulata. 



* * * Papillse large and inflated. Type, E. tricolor. 



