12 



JAMES A. GRIEG 



[REP. OF THE "MICHAEL SARS" NORTH 



the "Travailleur" show, however, that its southern distri- 

 bution extends to Cape Garnet, or to 25" 41' N. and 

 that it descends to a depth of 1 9 IS m. 



Labidoplax digitata Montagu. 



Holotlmria digitata Montagu. Transact. Linn. Soc, vol. 11, 1815, 

 p. 22, tab. 4, fig. 6. 



5 /s. Stat. 21. 35 : 31' N., 6 C 35' W., 535 m., yellow sand, temp. 

 1 1 .52 ~ Cel. One specimen. 



Labidoplax digitata is known from the Mediterranean 

 and the west coast of Europe northward to Great 

 Britain. Its bathymetrical distribution is from 18 — 618 m. 



ASTEROIDEA 



Pontaster tenuispinus Diiben & Koren. 



Astropecten tenuispinus Diiben & Koren, Kgl. Vet. Akad. Handl. 

 1844 (1846), p. 251, tab. 8, figs. 20—22. 



9 — ,0 s. Stat. 102, 60° 57' N., 4 C 38' W., 1098 m., dark sand 

 and clay, temp. — 0.9° Cel. Common. 



The largest specimen measured: arm-radius 77 mm., 

 disc-radius 14 mm., the smallest specimen was 33.5 mm. 

 and 6.5 mm. respectively. In 10 specimens of different 

 sizes varied r : R, between 1 : 4.47 and 1 : 5.9. 



The specimens belong to the v ariety platynota Sladen 1 ) 

 from the cold area of the Faroe-Shetland channel. They 

 have a paired arrangement of the marginal plates, spatuli- 

 form pedicellariae and a not very prominent papularium. 

 The armature of the adambulacral and marginal plates 

 as well as the dorsal paxillae was large and well developed. 



Benthopecten spinosus Verrill. 



(PI. 4, fig. 1). 



Benthopecten spinosus Verrill, Amer. Journ., ser. 3, vol. 28, 1884, 

 p. 218. 



. Stat. 70, 42° 59' N., 51' 15' W., 1100 m., temp. 3.7 : Cel. 

 One specimen. 



'-- --- : :. Stat. 95, 50° 22' N., IT 44' W., 1797 m., temp. 3.5° 

 Cel. 5 specimens. 



%— Vs. Stat. 101, 57 ; 41' N., IT 48' W., 1853 m., hard clay, 

 temp. 3.3" Cel. 12 specimens. 



All the specimens were more or less mutilated. Only 



in 4 specimens from stat. 101 was at least one of the 

 arms intact. These four specimens measured: 



mm. mm. mm. mm. 



Arm-radius 52 48 38 32 



Disc-radius 7 6 5.5 5 



Breadth of arm at base 7 5.5 5 5 



r:R 1:7.4 1:8 1:6.9 1:6.4 



A:R 1:7.4 1:8.7 1:7.6 1:6.4 



Number of dorso marginal 



plates 27 26 22 20 



') Sladen: Asteroidea, Rep. Sci. Res. "Challenger", Zool. vol. 3. 

 1889, p. 29, tab. 6, fig. 7, tab. 7, figs. 3 & 4. 



The largest specimen has a disc-radius of 11 mm. 

 Thus all of the specimens were younger individuals. 

 Verrill mentions specimens that were twice as large as the 

 largest of the specimens from the "Michael Sars". 



The species varies greatly with respect to the disc- 

 overing as well as the armature of the adambulacral and 

 marginal plates, as pointed out by Verrill. 5 — 6 papillae 

 are normally found in the inner row on the adambulacral 

 plates, but the number may vary between 4 and 7. One 

 large papilla and a small one outside of it are normally 

 found in the transverse row. But two large papillae may 

 also occur, one outside the other as in Pararchaster 

 semisqaamatus Sladen, or a small papilla may be situated 

 on either side of the large papilla. Also two small 

 papillae may be found instead of the small one outside the 

 large one. One or two large spines besides some very 

 small ones are found on the ventro-marginal plates. One 

 large spine is most commonly found on the dorso- 

 marginal plates, two such spines being an exception. 

 Moreover most of the plates have some spinelets most 

 commonly grouped around the large spine. These spine- 

 lets were in some specimens entirely wanting however 

 (pi. 4, fig. 1). Of the large spines the one on the medial odd 

 plate of the disc-angle is larger and stouter than the rest. 

 In a specimen from stat. 95 (disc-radius 8 mm.), this 

 spine was 8.5 mm., while those on the adjoining plates 

 measured 6 mm. In an other specimen from stat. 101 

 (disc-radius 5 mm.) these measurements were 5.5 mm. 

 and 3.5 mm. respectively. 



In two specimens, the medial odd marginal plates 

 were bifurcated in one of the angles of the disc. The bifur- 

 cation included not only the dorsal but also the ventral 

 plate. Each of these plates was furnished with a large 

 spine. 



The peculiar "spiracle-like or double comb-formed" 

 pedicellariae on the actinal interradial area were observed 

 only in some of the larger specimens. The number of 

 pedicellariae seems to vary greatly. They were absent in 

 some specimens, while a number of them were met with 

 in others of a similar size. The inter-radial areas have a 

 varying number of pedicellariae even in the same indi- 

 vidual. Thus — 1 — 2 — 1 — 2 pedicellariae were observed 

 in a specimen from stat. 95 (disc-radius 8 mm.). No 

 pedicellariae could be found between the ventro-marginal 

 plates. 



Verrill 1 ) has correctly referred Parachaster semisqua- 

 matus var. occidentalis and Parachaster armatus des- 

 cribed by Sladen in his report on the "Challenger" 

 Asteroidea 2 ), to that species. Pararchaster fished E. Perrier 



') Proc. U. S. Nat. Museum, vol. 17, 1891, p. 245, Cfr. Amer. 

 Journ. ser. 3, vol. 49, 1895, p. 129. 



-') Op. cit. p. 10 & 19, tab. 1 figs. 5 -6, tab. 4, figs. 5—6. 



