130 "TEKRA NOVA' EXPEDITION. 



External Fkatures. 



Tlic cliii'f points ill ihe cxlevnal uppearaiice of L. ■•<riitti whidi servo to dislinguisli 

 it IVoin L. i-timii/(if'fs urc as follows: — 



The skiu is cumparativL'lv smooth, and not tlirown into niarkcd wi'inklcs and 

 fnrrcjws. 



The liead is usually Wlunt and rounded in front. The snout is, liowever, evidently 

 capalilc of some extension, as in a small number of individuals it has been fixed iu a 

 more tapering form. 



The young specimens do not appear to coil up venti-ally in a spiral when killed, 

 as do th(.>se of L. roi-riKjatiis. 



The mouth (PI. II, fig. 1) is a lougitudiual slit, but not nearly so elongate as iu 

 the other species. In the largest imlividual it measures 5 mm. iu length. The 

 lips are thrown into regular folds transversely to the long axis of the mouth. 



There is in many cases a more or less well-marked transverse groove behind the 

 cephalic slits. This is especially noticeable on the ventral side (PI. II, fig. 1), where 

 it runs back in the middle line to meet the anterior end of the mouth, thus forming a 

 V-shaped furrow. 



The cephalic slits are very deep and clean-cut, measuring about 4 mm. in length 

 m the largest individuals. 



The proboscis-pore (PL II, fig. 1) is, as usual, a vertical slit at the tip of the 

 snout, crossing at right angles a slight groove which joins the anterior ends of the 

 cephalic slits. 



In length, complete specimens (of which there are few) measure from 2 • 4 cm. to 

 10' 7 cm. The larger specimens are all fragmentary, and it is impossible to guess at 

 the maximum length proliably attained ; but this would seem to be certainly very 

 much smaller than that reached by L. cornigafitf). In thickness, the largest fragment 

 measures about 8 mm. laterally and 6 mm. dorso-ventrally ; tlie other specimens vary 

 o-reatlv in thickness according to their state of contraction. 



No traces of the original colours of the species can be made out. 



Nearly all the specimens appear to be sexually immature. 



Internal Anatomy. 



JS,Jj/-/rii//.- The outer epithelium (PI. II. fig. o, Ep.) consists of very tall ciliated 

 cells, witii numerous smaller interstitial cells at their I)ases. Between the tall epithelial 

 cells are scattered many large club-shaped cells (PI. II, fig. 3. (il.-) full of a refractive 

 yelIowish-1 irown secretion. 



Below the epithelium there is a thin but solid-looking basement-membrane (B.M.), 

 scarcely as deep as the epithelium itself. Beneath this again there is a thin layer of 

 circular muscle-fil)res (CM'".). A well-developed and conspicuous, deeply-staining layer 

 of large glandular cells (GI.) succeeds this, resting immediately upon, and being partly 



