12 



basal end of the carina render it easy enough to distinguish this species from those it shows 

 affinity to in other regards. 



Torrether witli Poecilasma excavatuni, P. diibiuni and P. obliqmuit, a form of Poecilasma 

 was collected, about the nature of which I dare not pronounce an opinion with certainty. This 

 form is represented by a single specimen. The length of its capitulum is 7 mm., the peduncle 

 is about as long as the capitulum, cylindrical, distinctly ringed. It has the scutum divided into 

 two segments and, what has never been observed in any species of this genus, the tergum 

 also divided in two segments. The fissure runs in continuation to the fissure of the scutum 

 and has the same character in the terga of both sides. The terga do not look quite normal, 

 however, as they are only partly calcified : a relatively large part of the surface of the tergum 

 being occupied by chitinous substance. 



In fig. 9, PI. I I give a drawing of the outlines of this curious form, magnified .slightly 

 over 5 diameters; in fig. 10 the ape.x of the scutum is represented with the division of the 

 tergum magnified 36 diameters. I feel at a loss to decide whether this form is normal, in which 

 case it would represent a very interesting section of the genus Poecilasma, or what seems more 

 probable provisionally, a pathological abnormality being caused by mutilation and regeneration 

 of the parts that have been broken off. . . . 



N.B. This form has been labelled P. excavattim^ varietas. 



At the same Station (253) still another form oi Poecilasma was collected. It is represented 

 by a single specimen only; like P. fissum, P. excavahmi etc. it has the capitulum composed of 

 .seven valves and it is also nearly related to these species in other regards. Its peduncle seems 

 to be broken off, but the surface of the part remaining bears numerous microscopic spines. The 

 smaller segment of the scutum terminates at its tergal extremity in a point, so that no real 

 tereal marg-in is formed : in this retjard this form resembles P . fissiim more than P . excavatum. 

 It differs from both species in the smallness of its terga, its carina being a little longer than 

 in these species. 



The length of the capitulum of this form is 5 mm., that of the part of the peduncle 

 found attached to the capitulum about 2 mm. It was collected at a depth of 304 m. As the 

 specimen does not seem to be quite complete I think it better not to introduce it into the 

 .system under a specific name. 



6. Poecilasma odliqunm n. sp. PI. I, fig. 11 — 22. 



Capitulum slightly uns\-mmetrical, tergum rudimentary and concealed in the membrane 

 between the two scuta; carina with a prominent heel, terminating in a small imbedded fork. 

 Cirri short, partly rudimentary. 



General appearance (PI. I, fig. 11 and 12). Capitulum of oblique lenticular .shape, 

 placed in such a way to the peduncle, that its base is covered at the right side more than at 

 the left. Scuta in the larger specimens distinctly furrowed. 



