ASCIDIANS OF THE PHILIPPINES VAN NAME. 



147 



It was also obtained by the Sihoga Expedition in latitude 8° 23.5' S.; 

 longitude 119° 4.6' E., 64 meters. (Sluiter, 1909.) Caullery (1909, 

 p. 46) evidently inadvertently attributes the above species N. fascicu- 

 lar is of von Drasche to the Philippines. It has not been found there, 

 unless A 7 , thompsoni should eventually prove to be identical with 

 von Drasche's fascicularis. 



Family DIDEMNIDAE Verrill, 1871. 

 Genus DIDEMNOPSIS Hartmeyer, 1903. 



DIDEMNOPSIS JOLENSE, new species. 



Colony of elongate outline and rather thin flattened form in the 

 only good specimen. Length, 24 mm. ; greatest width, 10 mm. ; thick- 

 ness, 4 to 5 mm. Test rather easily torn, translucent, of a light, 

 smoky brown color, due both to pigment cells in the test and thoracic 

 region of the mantle, and to diffused color in the 

 test and tissues of the zooids. No spicules; zooids 

 arranged in curved rows probably constituting 

 only a few systems, or perhaps only one. 



Zooids rather large, up to 3 mm. long in the 

 partially contracted preserved state. Body 

 strongly constricted between the thorax and abdo- 

 men ; a very long strong tapering muscular process 

 extends obliquely ventrally and posteriorly out 

 into the test from this constricted region; club- 

 shaped vascular processes also extend into the test 

 from some zooids. Branchial aperture 6-lobed, 

 and provided with a strong sphincter ; atrial aper- 

 ture plain or very obscurely lobed; situated at the end of a very 

 short tubular extension of the middle dorsal region of the thorax, 

 or in some cases scarcely produced at all. No atrial languet. 



Mantle muscles composed chiefly of longitudinal fibers on the 

 thorax ; not conspicuous on the abdomen. 



Tentacles apparently of three sizes. The writer was not successful 

 in counting them, on account of the strongly contracted state of the 

 throax in all the zooids examined. 



Dorsal languets not demonstrated for the same cause, though 

 there is no reason to doubt their presence. 



Only three rows of stigmata could be discovered ; there are prob- 

 ably at least 15 in a row on each side. 



Stomach rounded-oblong, intestinal loop rather large, with several 

 valvelike constrictions in the proximal region of the intestine. 



No reproductive organs found in any of the numerous zooids ex- 

 amined. The colony, however, contains some larvae. 



Fig. 97. — Dihemxop- 

 s1s jolense, new 

 species. x 17.5. 



