226 TAOE SKOGSBERG 



rostral incisur there is a rather sparse row of moderately long bifurcated bristles (fig. 2); this 

 row becomes more and more sparse posteriorly, and at the same time the bristles become shorter 

 and simple, and already at half the length of the shell it practically ceases altogether; single short 

 simple bristles may, however, be observed on the list along the posterior part of the ventral 

 edge of the shell. Within the posterior margin of the shell the list is rather broad and has 

 from about 20 to 25 short bristles and outside these a varying number of peculiar formations, the 

 nature of which I have not succeeded in establishing with full certainty; probably they are a sort 

 of pores, at any rate they somewhat resemble these formations; seen from the side, they have 

 about the type reproduced in the accompanying figure 3, some of them at least seem to have, 

 if I am not mistaken, an extremely short and fine hair (the verification of this is uncertain 

 even with a magnifying power as large as Reichert's ocular 4, Leitz' immers. Vig). On 

 the part between the list and the edge of the shell, both along the ventral edge and posteriorly, 

 there are practically no medial bristles at all. The selvage is rather broad along both the anterior 

 and posterior edges of the rostral incisur; on the other hand it is rather narrow along the anterior 

 edge of the rostrum and along the ventral margin of the shell; it extends, however, rather consi- 

 derably outside the edge of the shell even in these parts. It has close, even and fine, in most cases 

 almost invisible cross-striation, and is exceedingly finely serrated at the edge, almost quite even. 



First antenna: — The posterior distal bristle of the third joint is generally some- 

 what longer than the bristle of the anterior side of this joint and also somewhat longer than 

 half the length of the fourth joint; the anterior of these two bristles is fixed at about a third of 

 the length of the joint. The two bristles of the fourth joint are generally subequal, not quite 

 as long as the fifth joint. All the bristles mentioned seem, however, to show a not inconsiderable 

 variation with regard to their length. The sensory bristle of the fifth joint is about as long as 

 the anterior sides of the second to the fourth joints taken together; of its thirteen sensory fila- 

 ments the ten proximal ones are about a third of the length of the whole bristle and are rather 

 considerably thicker than the distal ones, from which they are, in addition, separated by a 

 distinct gajD; the two following ones are only a quarter to a fifth of the whole length of the bristle; 

 the remaining, distal one is situated near the point of the bristle and is very short and narrow; 

 they are all of about the same thickness throughout whole tlieir length and quite naked. The 

 a-bristle of the seventh joint is about as long as the fifth joint, the bristle of the sixth joint 

 is somewhat shorter. The bristles of the third, fourth and sixth joints and the a-bristle of the 

 seventh joint are all furnished with short, fine hairs. Of the bristles of the seventh and eighth 

 joints the b-bristle is about the same length as the five distal joints and has five sensory filaments. 

 The c- and f-bristles are subequal and about double the length of the six distal joints; each 

 of these two bristles has ten sensory filaments. The g-bristle is somewliat longer and is character- 

 ized by eleven sensory filaments. The proximal filaments on these bristles liave from one to 

 six rather short and weak secondary spines, the distal ones are smootli. The sensory tube-like 

 bristles d and e are subequal, about the same length as the six distal joints taken together. 

 Pilosity: The second joint is very sparsely furnished with hairs. 



iS e c o n d a u t e n ii a: — P r o t o p o d i t e: Length about 0,7 — 0,8 mm. in specimens 

 about 2,;j nun. long. The incdial-distal bristle (fig. 7) is sliort, about as long as or even somewhat 



