13 



The lateral processes or digitations are thirty-eight in number, being disposed 

 nineteen on either side, irregularly, one upon the other, and all directed for- 

 wards, converging towards the orifice of the oral sheath. The length of the 

 entire mass of digitations is two inches ; but the longest of these processes, when 

 its free extremity only is measured, does not equal one inch ; for they adhere, 

 as it were, by their inner surfaces to the parietes of the head, some not ex- 

 tending as far as the anterior margin of the head, but terminating at difierent 

 distances from it, while others project a few lines beyond it. They are mostly 

 of a flattened triedral form, and become smaller towards the extremity, where 

 is situated the orifice of a canal which traverses them longitudinally. 



There is not the slightest appearance of acetabula on any of these processes, 

 but the exterior superficies is more or less rugose, and in most is canaliculate 

 near the upper margin. The largest process (o'. pi. 1 ; m . pi. 2 ; k. fig. 1 . 

 pi. 3.), which lies next the hood, is papillose, and appears at first sight to form 

 a part of the hood, but is separated from it by the narrow groove above men- 

 tioned. 



Each of these hollow processes contains an annulated cirrus or tentacle 

 [p. pi. 1 ; fig. 3. pi. 2 ; c. pi. 7.), about a line in diameter, and from two inches 

 to two inches and a half in length ; they are consequently much longer than the 

 digitations themselves, the canals in which they are lodged being continued in the 

 substance of the sheath towards the origins of the nerves (fig. 5. pi. 7.). These 

 tentacles are of a rounded form, but rather flattened towards the extremity. A 

 few of them were in the specimen protruded from their sheaths to the extent 

 of half an inch, but the rest were completely retracted so as not to be visible, 

 and on laying open some of the canals, the extremities of several were found 

 as far as a quarter of an inch from the apertures ; so that they appear to possess 

 considerable projectile and retractile powers. 



Of the digital processes nineteen have been enumerated on either side ; but as 

 the hood has two perforations anteriorly from which tentacles similar to those 

 of the digitations are also protruded, we may consider this part as two digi- 

 tations conjoined along the mesial line, and so reckon with Rumphius the even 

 number of twenty digitations on either side of the head. With respect to the 

 tentacles, to their number must be added four others, which project immediately 

 beneath the margin of the hood, like antennae, one before and one behind each 



