LAMELLISABELLA MINUTA 



443 



first specimen. The overall length of the latter 

 is probably between 55 and 60 mm. 



No spermatophores have been found. 



The tube of L. minuta is very characteristic. 

 Its mouth opens out as a broad funnel, like 

 lhatoi L.johanssoni (Ivznov, 1957, 1960c), and 

 indeed, like the latter species, the front end of 

 the tube has a series of funnels stacked one in- 

 side the other. The front ends of the two tubes 

 are shown in Fig. F169. Each funnel corre- 

 sponds to a single segment and the tube appears 

 in essence to be segmented, but they very 

 rapidly disappear as we pass backwards from 

 the mouth of the tube, and then right to the 

 end it is completely uniform and homogene- 

 ous (Fig. F169C). 



A small distinct part of the tube (with fun- 

 nels and segments) is brown, thin-walled and 

 transparent. Then the tube gradually becomes 

 lighter, turning a pale yellow-brown, and still 

 more transparent. The hind half of the tube 

 (or perhaps even more than a half) is whitish 

 transparent and soft. Finally, the hindmost 

 part has colourless laminated limp walls. 



The incomplete tube (lacking the hind end) 

 of the larger individual is 147-5 mm long, the 

 one with young animal 119 mm. The anterior 

 diameter of the tubes are respectively 04 and 

 0-35 mm. 



L. minuta is sharply distinguished from the 

 other species of this genus by the small size of 

 the body. The most reliable measure of the 

 size of a pogonophore is the breadth of the 



mesosoma. In this species the diameter is only a quarter to a third of that in 

 the other species. Other important distinctions are the small number of ten- 

 tacles, the structure of the keels of the bridle and the size of the cuticular 

 adhesive plaques. The horseshoes on the metameric region of the metasoma 

 in L. minuta have shorter ends than in the other species. A number of 

 features of the four species of Lamellisabella are compared in Table 6. 



Fig. F169. 



Lamellisabella minuta : 

 A-C - successive parts 

 of the tube. 



