ALBERT

Description: Eleven samples of pelagic tunicates were found in the material collected during the Snellius Expedition 1929-30. In these, seven species, viz., two pyrosomas and five salpas, are included. In addition, a few old specimens of another species of Pyrosoma were found in the collection of the Leiden Museum. Thus, the following eight species are recorded in the present short paper. 1. Pyrosoma spinosum (Herdman) 2. Pyrosoma verticillatum cylindricum Metcalf & Hopkins 3. Pyrosoma atlanticum atlanticum (Peron) 4. Ritteriella picteti (Apstein) 5. Salpa fusiformis Cuvier 6. ? Salpa cylindrica Cuvier 7. Thetys vagina (Tilesius) 8. Pegea confoederata (Forskal) Most of the specimens are preserved in formalin and these, especially the salpas, are all in a poor condition. In the salpas, most of the soft tissues, inclusive of muscle bands, has been lost as if the specimens had come from the stomach contents of fishes. Fortunately, however, the size, approximate outline, and situation of the nucleus could be determined, as well as those of the stolon. In some specimens, some traces of muscle bands were visible. All these features, together with test characters and the situation of the dorsal ganglion deducible from the anterior base of the gill, enabled me to identify most of them definitely.\nI want to express my cordial thanks to Dr. W. Vervoort of the Rijksmuseum van Natuurlijke Historie at Leiden for his generous help during my

Description: I was strongly impressed by the striking resemblance between the ascidian genera Ciallusia Van Name, 1918 and Pterygascidia Sluiter, 1904 when in 1957 I examined some specimens of Ciallusia longa Van Name, 1918, collected from Philippine waters and deposited at the United States National Museum (Tokioka, 1967: 136). C. longa is closely related with Pterygascidia mirabilis Sluiter, 1904, collected from off Timor by the Siboga Expedition, in general appearance of the pedunculate body, situation of the branchial and atrial apertures, structure of the branchial siphon, arrangement of body muscles divided into parts, and in the essential structure of the branchial sac, alimentary canal and gonads. The former, however, seemed to differ distinctly from the latter in the absence of a pair of remarkable fin-like semicircular extensions of the dorsal lobes of the atrial aperture and in having a series of dorsal languets instead of the dorsal lamina of a narrow, plainly edged membrane. Especially the last difference seemed very significant from a systematic point of view in Ascidiacea, because the plain membranous dorsal lamina is generally considered to be exceptional in the order Phlebobranchia.\nRecently, I had the opportunity to examine twenty specimens of C. longa collected by the Snellius Expedition on 5 September 1929 at Station 60*, 6\xc2\xb058.0\'N 121\xc2\xb052.5\'E, in the Basilan Strait between the islands of Basilan and Mindanao, 72-80 m deep. To my surprise, the pair of wing-like elliptical extensions of the dorsal lobes of the atrial aperture which are supposed to be unique to P. mirabilis were found very clearly on 19 of the 20 specimens (fig. 1 A, B). I thought that I found a structure of uncertain meaning on the dorsal side of the body just posterior to the atrial siphon in the specimens of