37 



marginem pallii denique 4 anteriores, 2 ad marginem anticum sibi approximati et 2 alii ma- 

 jores magis a se remoti raargini exteriori propiores ad basin tentaculorum adsunt. Series 

 longitudinalis processuum irregularium pr&terea adest in dorso partis posticse corporis. Pes 

 valde angustus sublinearis postice acuminatus. Tentacula dorsalia longe a se remota brevia 

 et crassa laraellosa ex parte retractilia. Velum obsoletuni. Tentacula labialia nulla, Anus 

 dorsalis pone medium situs, branchiis minimis et rudimentariis circumdatus. Color albidus; 

 lougit. 7. Mm. 



Habitat rara ad insulas Lofotenses in prof. 120200 orgyarum, fundo argillaceo. 

 This species is immediately distinguished from the 2 other species T. clavigera and T. lacer, 

 by the peculiar and strong development of the mantle, as also by the few (4) processes on 

 the anterior extremity, and the peculiar forked longitudinal carena, along the back. 



Gonieolis typica, M, Sars, 



(PL IV. fig. 1-11). 



Gonieolis typica M. Sars. n Beretning om en i Sommeren 1859 foretagen zoologisk 

 Reise ved Kysten af Romsdals Amt," pag. 4. 



Also this very peculiar nudibranch, which already in 1860 was shortly noticed by my 

 Father, seems to be a genuine deep-sea form which, as is well known, is something very 

 unusual in this group of molluscs which comprises scarcely any other than littoral or sub- 

 littoral forms. 



The following description is for the most part after the manuscript of my Father. 



The body resembles (see fig. 1. & 2.) a snail; it is oblong, about 12 Mm. long; in 

 the anterior part 5 Mm. wide; towards the posterior part gradually narrower and quadrangular, 

 as the back, which forms a distinct mantle with projecting tolerably thick side-borders, is 

 nearly quite flat or only slightly convex, and the sides of the body are high (nearly as high 

 as the body is wide) and somewhat hollowed. The mantle, which every where is narrower 

 than the foot, is (see fig. 1) widest in the anterior part, where it takes its beginning im- 

 mediately behind the dorsal tentacles, and becomes gradually narrower towards the pos- 

 terior part which terminates in a point. The foot is tolerably thick, furrowed in front and 

 with the anterior corners rounded; it is wider than usual in the Eolis, only a little narrower 

 at the posterior end, and obtusely rounded, and both longer and wider than the mantle. The 

 head is wide (as wide as the mantle) nearly quadrilateral, and bears on the posterior part, 

 immediately in front of the anterior end of the mantle, the dorsal tentacles (a. a) in front 

 of which it gradually (see fig. 2) inclines downward, and has here a wide straightly truncated 

 velum (b) (which is wanting in the Eolis) from .the upper side-corners of which the labial 

 tentacles (c. c) arise. 



