G<xtly Marine Lahuvatory, St. Andrews. 107 



and there is less regularity. The edge of tiie collar thus 

 ditlers under a lens, and the collar is often shorter from side 

 to side. In front of the denticulated collar a distinct 

 conical process passes forward to the space between the 

 branchiae. On the ventral surface, again, the body-collar 

 has not the prominent lateral edges seen in M. cristata. 



Tlie post-branchial hooks are diagnostic, and their position 

 is the same as in M. cristata. They have a broad, almost 

 ovoid, flattened shaft, the base of which is often oblique. 

 Anteriorly it somewhat abruptly narrows, and is bokily 

 curved forward as a rounded, tapering, apparently solid hook 

 with a sharp point. The broad shaft is marked by fine 

 longitudinal lines, which are continued beyond the curve and 

 toward the tip of the hook, and also marked by siijilitly 

 curved cross-striae which jniss forward to the curve or neck 

 of the hook and then cease, the tip being homogeueons and 

 clear. It is moved by powerful muscles attaelied to tiie 

 shaft. The concavit^'of the hook has a tliick layer of chitin, 

 but no canal could be made out. Such a hook differs from 

 that of Melinna cristata in outline and structure, as well as 

 in the absence of the canal at the tip. 



Tiie bristles have the same structure as in M. cristata, viz. 

 translucent, striated shafts, and winged tapering tips, and 

 they are accompanied by the shorter series as in the jjrevious 

 form. The hooks resemble tliose of the other species, but, 

 whilst in M. cristata they often show five teeth, in M. elisa- 

 hethoi four is the usual number, and the curves slightly 

 did'er. 



The tube of this form consists of tough secretion coated 

 with a little mud, and having fiagnients of shell attached 

 here and there by the edges. The gastric juice of the fishes 

 does not seem to affect the tubes much, though their in- 

 habitants are rapidly softened. The tubes of the Norwegian 

 examples are of tough secretion coated with fine mud, with 

 lierc and there an arenaceous Foraminifer. 



It is curious that this species has never been tossed on 

 shore at St. Andrews. it probably inhabits the deeper 

 water, and is the common form in Norway. 



Grube describes Melinna palmata from St. Male, where he 

 obtained a single specimen, as having a smootli (entire) 

 margin to the dorsal collar on the fourth bristled segment, 

 instead of the fimbriated margin of M. cristata and M. elisa- 

 betha. There are eight branchite, which diU'cr at their f)asc 

 from those of M. cristata, and in the spirit-preparation the 

 anterior and the inner filaments of the posterior branchia 

 are longer and more pointed than the rest. The frontal 



