FISHERY BULLETIN: VOL. 74, NO. 4 



ments: basitrichs 14 x 1.1 - 16.4 x 1.6, 28 x 3.3 - 31 

 X 3.8-4.4; microbasicp-mastigophors 21 x 3.3 - 23 

 X 3.8. Acontia: basitrichs 32-40 x 3.8-4.4 /xm. 



Horniathia nodosa (.-') (Fabricius 1780) 



OCCURRENCE.-41°34'N, 68°40'W, 128 m, 

 sandy silt, 1 specimen. 



GENERAL CHARACTERISTICS.-The col- 

 umn is divisible into scapus and scapulus, the 

 former being provided with a thin periderm and 

 rather large, acuminated tubercles spread over the 

 surface. The color of the scapus is proximally dark 

 greyish brown, distally brown. Bordering upon the 

 scapulus there are 12 large marginal tubercles. 

 The pedal disc is not excavated; there are traces of 

 mussel shell. The tentacles lack bulbous swellings 

 on the abaxial side. They are arranged in four 

 cycles. The actinopharynx and the sphincter agree 

 with those in H. nodosa (cf. Carlgren 1893). The 

 number of mesenteries is 96 (6 -t- 6 -H 12-1-24 pairs), 

 the perfect ones being 24 pairs in the distal part of 

 the column. Immediately above the margin of the 

 actinopharynx there are 20 pairs of perfect mes- 

 enteries. Only the six pairs of protomesenteries 

 are sterile. The morphology of the retractors, 

 parietobasilar, and basilar muscles agrees with 

 that in typical H. nodosa. The length of the pre- 

 served specimen is: scapus 16 mm and scapulus 7 

 mm. The size of the pedal disc is 36 x 49 mm. The 

 sizes of the different nematocyst types differ only 

 slightly from those described in H. nodosa (see 

 above). The large number of perfect mesenteries 

 is, however, remarkable. 



In view of the many morphological similarities 

 between this specimen and typical H. nodosa, I 

 consider it as an aberrant specimen of this species. 



Actinauge ferr////' McMurrich 1893 



OCCURRENCE. -42°11'N, 65°56'W, 229 m, 

 gravel, 1 specimen; 42°20'N, 67°28'W, 289 m, sandy 

 gravel, 1 specimen; 42°50'N, 69°00'W, 187 m, 

 sand-silt-clay, 1 specimen. 



GENERAL CHARACTERISTICS.-The mor- 

 phology of these specimens agrees with earlier 

 descriptions of the species (cf. McMurrich 1893; 

 Carlgren 1933). The scapus is equipped with a 

 greyish-brown or brown periderm; it has a re- 

 ticular appearance, arising from transverse as 



872 



well as longitudinal, rather low, furrows. Distally 

 there are 12 coronary tubercles. The firm wall of 

 the scapulus is often whitish and is provided with 

 24, white, scapular ridges, proximally fusing two 

 by two into 12. The scapus is cylindrical or dome- 

 shaped, with the length 29-30 mm. The diameter of 

 the scapus is proximally 17-30 mm and distally 

 19-20 mm. The length of the scapulus is 14 mm. The 

 pedal disc is strongly excavated, often embracing 

 sand grains. The long and tapering tentacles are 

 arranged in four to five cycles. The outer tentacles 

 are basally provided with abaxial swellings, which 

 give rise to distinct processes. There are four 

 cycles of mesenteries. Six pairs (including the two 

 directive pairs) are perfect and sterile. 



NEMATOCYSTS.-ScajoMs: basitrichs 8 x 1.6 - 

 23 X 4.4. Tentacles: basitrichs 12 x 2.2 - 27 x 2.7- 

 3.3, ca. 40 X 3.8 (rare); microbasic p-mastigophors 

 24.5 X 3.8-5.2 - 38 x 8.2; spirocysts 19 x 3.3 - 37 x 

 4.4-6; 46-56 x 5.5-7. Actinopharnyx: basitrichs 13 

 X 1.6 - 17 X 2.2, 28-50 x 3.3; microbasic p- 

 mastigophors 22 x 3.8 - 29 x 4.4. Filaments: 

 basitrichs 11 x 1.1 - 17 x 2.2; 28-30.5 x 3.3, 

 microbasic p-mastigophors 19 x 3.8-4.9 - 35 x 4.4. 

 Aco7itia: basitrichs (14 x 2.2 -) 26 x 3.3 - 36.5 x 

 3.8-4.4 jum. 



Phelliactis americana n. sp. 



HOLOTYPE.-Specimen collected by the vessel 

 Delaware from the type-locality (station number 

 27) on 19 February 1963 with an otter trawl. 

 Deposited in the U.S. National Museum, catalog 

 number USNM 54323. 



TYPE-LOCALITY.-42°48'N, 63°42'W, 366 m, 

 temperature -t-1.7°C. 



PARATYPE.-Specimen collected by the vessel 

 Albatross IV from station number 73 (42°17'N, 

 65°55'W, 238 m, gravel) on 15 August 1968 with a 

 1-m Naturalist dredge. Deposited in Northeast 

 Fisheries Center, Woods Hole. 



DIAGNOSIS OF HOLOTYPE.-Column firm, 

 divisible into scapus and scapulus; somewhat 

 asymmetric. Scapus distally with 48 rows of large, 

 sometimes acute, tubercles. Scapular ridges about 

 70. Sphincter mesogloeal, and alveolar, very 

 strong. Tentacles about 190, conical, and long- 

 itudinally furrowed with basal, abaxial swellings. 

 Mesenteries in five cycles, 12 pairs being perfect 



