REPORT ON THE TUNICATA. 117 



the microscope reveals that this is due to the presence in the interior of a number of 

 trabecules, which form a close network and cause projections on the surface from the 

 sinking in of the matrix over the meshes (PI. XIII. fig. 1). The trabecule (t.m.c.) 

 arc of a rich brown colour, and stand out from the surrounding material (t.m.), which 

 is much paler and less opaque. Probably these trabecuke are of the same nature as the 

 cornified liars of test matrix separating the blood channels in the peduncle of Culeolus 

 murrayi. 



The Mantle is a very delicate membrane, and the musculature is feebly developed. 



The Branchial Sac is very delicate and has several slight folds on each side. These 

 are formed in the usual manner, and each has about four internal longitudinal bars (PI. XL 

 fig. 9, br.f.). The transverse vessels are narrow and are all of one size. The internal 

 longitudinal liars are wider, forming the strongest part of the network. 



The meshes are large and are nearly square, usually a little elongated transversely 

 (PI. XL fig. 9) ; in the row on each side of the dorsal lamina they are more elongated, 

 the transverse extent being to the longitudinal in the proportion of six or seven to four ; 

 no secondary transverse vessels, fine longitudinal vessels, or other irregularities were 

 observed. 



Calcareous spicules are present in the internal longitudinal bars. They are not very 

 numerous but are large and branched slightly, resembling those of the branchial sac of 

 Culeolus murrayi. 



Ti,r Dorsal Lamina. — The languets placed along the dorsal line are large and triangular, 

 but rather broader and blunter than usual. 



Tht Tentacles are branched, and are large compared to the size of the body. They 

 are sixteen in number, and are of two sizes placed long and short alternately. 



They are not much branched, and contain numerous and large calcareous spicules of 

 the same form as those in the branchial sac. The branches are rather long and narrow. 



A single specimen of this small species, slightly injured, was obtained off the east 

 coast of North America, south from Long Island. After the publication of the part of 

 my Preliminary Report in which this species was described as new under the name of 

 Culeolus suhmi, a MS. of Dr. R. von Willemces Suhm was placed in my hands, in which 

 a sketch and a brief description, under the name of Boltcuia jicrlata, n. sp., evidently 

 refer t«> this specimen. I have consequently substituted Suhni's specific name. 



Station 44. May 2, 1873 ; hit. 37° 25' N., long. 71° 40' W. ; depth, 1 700 fathoms; 

 bottom temperature, 1"7 C. ; grey ooze (a blue mud). 



Culeolus moseleyi, Herdman (PL X. figs. 7-12 and PL XIII. figs. 3-4). 



Culeolus moscl- i/i, Ilerdman, Preliminary Report, Proc. Roy. Soc. EJin., 1880-81, p. 87. 



External Appearance. — This is a small species, but it has the body and the peduncle 

 both rather elongated. The general outline of the body is elongated pyriform, the anterior 

 being the narrower tapering end (PI. X. fig. 7). The outline is pretty regular, and 



