29 



longitudinal striation of the column wall, mentioned by Kwietniewski, was but slightly prono- 

 unced and if I am right in my identification, cannot be considered characteristic of the species. 

 The marginal tentacles were long and slender, and numbered 81. They were apparently 

 arranged in four cycles, their formula being 



i, 4, 



■i o 



ii 3i 2 >4 



i. 



I. 2, I 



4, 



'1 Oi 



!, 4, I -. 



The labial tentacles were about one-third the length of the marginals and were of the same 

 number, the median tentacle being present, although considerably shorter than the others. The 

 formula for their arrangement in cycles was apparently 



— 2, i, 3, 4 | 2, 3, i, 4 || 3, i, 4, 2, 4, i, 3 || 4, 1, 3, 2 | 4, 3, 1, 2 •-. 



Dimensions. — The length of the column was 4 cm.; its diameter at the margin 

 2.5 cm., and at the middle of the column 2.0 cm. The length of the marginal tentacles was 

 3.0 — 3,5 cm., and their diameter at the base was 1 mm.; the length of the labial tentacles 

 was 1.0 — 1.2 cm., and their diameter at the base about 1 mm. The length of the stomatodaeum 

 was 1.2 cm. 



C o 1 o u r. — The column was of a rather pale purple-brown, becoming lighter towards 

 the margin. Both sets of tentacles were almost colourless, a slight tinge of purplish-brown 

 being visible in some of them and appearing to indicate that their colourless condition was 

 the result of preservation. The stomatodaeum was pale, almost salmon-colour, 

 and the siphonoglyph colourless. 



Structure. — The muscle processes supporting the ectodermal mus- 

 culature of the column wall were well developed and showed a tendency to 

 arise in groups from conical elevations of the mesogloea, a tendency which 

 was less pronounced near the margin than lower down. 



As in the case of C. amboncnsis the parts were too much macerated 

 to allow of histological study, but by combining the study of sections with 

 dissections, it was possible to make out the arrangement of the mesenteries, 

 so far as their relative lengths were concerned (Text4igure VI). The directive 

 mesenteries extended to a distance of 9 mm. below the lower border of the 

 stomatodaeum and were succeeded on either side by a telocneme which 

 extended to the aboral pole. The third couple of protocnemes extended to 

 about 1.2 cm. below the stomatodaeum and the fourth couple to about 

 1.7 cm. The cleuterocnemes of the first quartette showed the typical alternating 

 arrangement so far as the brachycnemes were concerned, but no decided 

 alternation of length was discernible in the macrocnemes, these being for the 

 most part of about the same length as the fourth couple of protocnemes, 

 diminishing slightly, however, toward the dorsal mid4ine. 



The presence or absence of craspedonemes on the upper portions of 

 the mesenteries could not be determined, but they occurred throughout the 

 length of the telocnemes in considerable numbers and were slender in form. No reproductive 

 cells were observed in anv of the mesenteries. 



Fig. VI. 



Diagram showing the 

 arrangement of the 



mesenteries" of 

 Cerianthus sulcatus. 



29 



