EXPLORATION OF ALASKA. 241 
Of this species I have had a lot of specimens for examination, all 
preserved in spirits; partly (two) from the neighborhood of Bergen 
(Norway), kindly sent by Mr. Friele, partly (one) from the Frith of 
Kiel, sent by Prof. Moebius; but particularly (seventeen) from the 
coast of Denmark (Strib, lille Balt.) 
The individuals varied much in color. The variability of the color 
is noted by Alder and Hancock. They were whitish, or whitish sprinkled 
with brownish, or dark (bluish) gray, or yellowish, or brownish, or 
reddish-brown on the back, with whitish or yellowish sides and foot. 
The length reaching 12.0 mm., by a breadth of 8.0 and a height of 
5.0 mm.; the foot then about 4.0 mm. broad, the branchial leaves 
reaching to the height of about 1.0 mm. 
The back covered all over with the soft, slender, conical and pointed, 
erect (or curved) papilla of very different sizes, most of them small; 
between these are larger ones;! some of the largest divided into two 
or three points, and some of them connate and forming small crests, 
divided above into two or three points. The margins of the sheaths 
of the rhinophoria rather prominent, divided into several (six to eight) 
smaller and larger pointed lobes ; the club of the rhinophoria with about 
twelve to twenty leaves.2 The branchia, in both Norwegian specimens, 
with eight tripinnate leaves, otherwise with seven-to nine (as men- 
tioned by Meyer and Moebius). The anal papilla low, with several 
papillule and a star-shaped aperture; on a low crest, issuing from its 
posterior, is a strong papilla, The head and the tentacles (Plate X, 
fig. 146) as figured by Alder and Hancock (1. ¢., Plate 15, fig. 1), 
‘ The anterior margin of the foot with a fine transverse furrow (Plate X, 
fiz. 14a), The genital opening is a longitudinal slit (Plate XI, fig. 2). 
The peritoneum was mostly of reddish-brown color, 
The central nervous system showed® the cerebral ganglia rounded- 
triangular, not much flattened, a little larger than the more rounded 
visceral, which lie behind and on the outside of them and show a slight 
notch in the outside; on the inferior side of the visceral ganglia the 
pedal ones are set nearly perpendicular on the latter, connected by the 
1 Alder and Hancock, also Meyer and Moebius give eighteen to twenty 
leaves, Cf. the figures 7-8 of Meyer and Moebius, 
2 Collingwood (Ann. Mag. N. H., 3 ser, vi, 1859, p. 463) remarks that it 
¢ when not in motion bears a great resemblance to a miniature hedgehog.”’ 
* The representation of the system given by Hancock and Embleton (On 
the anatomy of Doris, Philos, Transact. MDCCCLU, Plate 17, f. 8) is not 
very like nature, 
