274 



DISCOVERY REPORTS 



St. 279. 4 mm. mesh net at back of trawl : 6 shells. 



St. 288. Young-fish trawl, 250 (-0) m. : 3 specimens; i m. tow-net, oblique, 73-0 m. : i specimen. 



The specific name of this species is taken from the long upper lip of the dorsal side 

 of the shell. It is one of the very few species which a beginner might venture to name 

 from the written description of the shell, as it is the only species with a shell of a tri- 

 angular shape when fully developed. At this stage the posterior "thorn" is always 

 wanting and the lateral points of the ventral side project in triangular-shaped portions 

 beyond the slits on the upper side. Boas (1886, p. 102) mentions that the smallest shells 

 which came under his observation (from Chinese seas) measured 2-5 mm. and the largest 

 (from the Atlantic) measured 9 mm. The specimen from St. 288 measured 7 mm. 



Distribution. This species is known from 40^ N (Schliemenz, 1906, p. 20), and 

 occurs in all seas between 40° N and 40° S. It is very abundant in Indian and Chinese 

 seas and off the Great Belt of Australia. 



Cavolinia gibbosa (Rang), in d'Orb., 1836. 



Hyalaea flava, A. d'Orb., 1836. 

 Hyalaea gegenhauri, PfefFer, 1880. 



St. 87. Young-fish trawl, 1000 (-0) m. : 3 shells. 



29° 27' 00" N, 15° 07' 00" W. 2 m. net, goo m. : 24 specimens. 



The fins of this species are generally trilobed, the apron is well developed and the 

 lateral appendages to the mantle are very long. The shell is very globular and has a 

 rounded upper lip measuring about one-seventh of the length of the shell when viewed 

 from above. It curves down over the mouth. The lateral points are very short and the 

 distance between them is considerably less than the breadth of the shell in the middle. 

 The posterior "thorn" is bent like a fish hook. 



The twenty-four specimens recorded from off the Canary Islands were taken from 

 the stomach of Naucrates. 



Distribution. Cosmopolitan except at the poles. Although a warm-water species it 

 avoids the immediate neighbourhood of the equator. 



Cavolinia inflexa (Lesueur), 1812. 



Hyalaea inflexa, Lesueur, 18 12-13. 



Hyalaea depressa, d'Orb., 1836. 



Hyalaea inflexa and labiata, Souleyet, 1852. 



Hyalaea vaginellina, Cantraine, 1840; Gegenbaur, 1855. 



St. 80. Young-fish trawl, 1000 m. : i specimen. 

 St. 87. Young-fish trawl, 1000 (-0) m. : 2 specimens. 

 St. 89. 2 m. net, horizontal, 180 (-0) m. : 8 specimens. 

 St. 268. I m. net, oblique, 73-0 m. : .' 2 young specimens. 

 2° 20' 00" S, 12° 45' 00" W. I m. net on trawl: i specimen. 



This species has trilobed fins and neither apron nor lateral appendages are much 

 developed. The shell is easy to distinguish from that of the other species, as the longi- 



