224 ABYLOPSIS TETRAGONA. 



Eastern Tropical Pacific. Considering, however, how closely it resembles 

 A. trigona, and how long the very common, and easily distinguishable A. esch- 

 schoUzii ( = quincunx) escaped notice, it is not unlikely that it may occur in the 

 Tropical Atlantic. 



ABYLOPSIS Chun, 1888. 

 Abylopsis tetragona (Otto). 

 Plate 14, figs. 6, 7; Plate 15, fig. 2. 



Pyramis tetragona Otto, '23, p. 306, taf. 42, fig. 2a-2e. 



Aglaja baerii Eschscholtz, '2.5, p. 743, taf. 5, fig. 14. 



Plethosoma cryslalloides Lesson, '26, pi. 4, fig. 2 (partim), '30, p. 64. 



Calpe pentagona QuoY and Gaimard, '27, p. U, pi. 2A, fig. 1-7; Blainville, '30, p. 132; '34, p. 134, pi. 



4, fig. 3; Lesson, '43, p. 449. 

 Aglaisma baerii Eschscholtz, '29, p. 129, taf. 12, fig. 5. 

 Abyla pentagona Eschscholtz, '29, p. 132; Leuckabt, '53, p. 56, taf. 3, fig. 1-6; '54, p. 11, taf. 11, 



fig. 1-10; KoLLiKER, '53, p. 41, taf. 10; Vogt, '54, p. 121, taf. 20, fig. 4r-7, taf. 21, fig. 3-6, 10-13; 



Huxley, '59, p. 40, pi. 2, fig. 2; Gegenbaur, '60, p. 349, taf. 28, fig. 17-19; Keferstein and 



Ehlers, '61, p. 14, taf. 3, fig. 5, 6; Spagnolini, '70, p. 21; Fewkes, '74, p. 318, pi. 3; Chun, '97b, 



p. 30; Lens and Van Riemsdijk, :08, p. 17, pi. 2, fig. 17-20. 

 'Diphyes calpe QuoY and Gaim.\rd, '34, p. 89, pi. 4, figs. 7-11. 

 Aglaisma pentagonum Leuckart, '53, p. 150, taf. 3, figs. 2, 3. 

 Eudoxia cuboides Leuckart, '53, p. 54, taf. 3, figs. 7-10; Muller, '70-'71, taf. 11, figs. 6, 7, taf. 13, fig. 



9; Chun, '85, p. 525, taf. 2, fig. 11; Bedot, '96, p. 375. Eudoxid. 

 Aglaismoides elongata Huxley, '59, p. 61, pi. 41, fig. 3. Eudoxid. 

 Aglaisma gcgenbauri Haeckel, '88b, p. 119, taf. 40. Eudoxid. 

 Calpe gegenbauri Haeckel, '88b, p. 164, pi. 39, 40. 

 Calpe huxleyi Haeckel, 'S8a, p. 36; '88b, p. 164. 



Aglaisma cuboides Chun, '97b, p. 30; Lens and Van Riemsdijk, : 08, p. 19, pi. 2, fig. 21. Eudoxid. 

 Abyla tetragona Schneider, '98, p. 89. 

 Abyla huxleyi Agassiz and May'ER, :02, p. 166, pi. 11, figs. 48. 



Abylopsis tetragona was taken from the following Stations: 4642,4646,4652, 

 4655, 4657, 4659, 4669, 4671, 4676, 4701, 4702, 4708, 4715, 4716, 4722, 4724, 

 4731, 4732, 4734, 4737, 4740. The material consists of 4 specimens from 3 

 surface, 93 from 20 intermediate, hawls with open nets, chiefly 300-0 fathoms. 



Its Eudoxid was taken at Stations 4655, 4657, 4676, 4679, 4681, 4715, 

 4724, 4673. 25 specimens in one surface, 18 in 7 intermediate, hawls with open 

 nets. The largest anterior nectophore is 8 mm., the largest posterior one 35 mm., 

 the largest Eudoxid 7 mm. long. 



My choice of Otto's name tetragona for this species, in place of the commonly 

 accepted pentagona, rests on Chun's statement that he has examined Otto's 

 type specimen (specimens?) which is still in good condition, in the Museum at 

 Breslau, and that he "erkannte sofort, dass thatsachlich die Abyla pentagona 

 vorliegt." ('97b, p. 31.) In the face of the statement, by one of the most 

 experienced students of coelenterates, that the type specimen of tetragona is 

 identical with pentagona, the more recent name must, of course, become a syno- 



