642 Proceedings of Royal Society of Edinburgh. [ sess . 
Lond ., 1854, p. 17, pi. i. fig. 14; A. pelagica, Ehrb., Mon. Ber. 
Ah., 1854, p. 238; A. hexactis, Ehrb., Abh. Ber. AJc ., 1872, pi. ix. 
figs. 1, 2 ; A. marylandica , var. ausonia , Cstr., Atti Accad. pontif. 
nuov. Lincei , Roma , 1875, p. 393, pi. vi. fig. 4. 
Dr Wallich distinguished as var. ft (Wallich, ibid., 1860, p. 48, 
pi. ii. fig. 14), forms having compartments with rounded inner ends 
and simple rays, and as var. y (ibid., pi. ii. fig. 15), those having 
the inner ends of the compartments truncate, and the rays con- 
spicuously ramose near their central ends, the branching of the 
rays being symmetrical with respect to a diameter of the valve. 
Peragallo (Diat. Baie d. Villefranche, 1888, p. 74) 'still adheres to 
Wallich’s .var. f3, naming it A. marylandica, var. major, but it 
appears to me hardly sufficiently distinct from the type to merit 
varietal recognition. Wallich’s var. y may be named A. mary- 
landica, var. ramosa. Forms named by Thum A. adriatica , Grun., 
and now in the collection of Mr Julien Deby, do not differ from 
A. marylandica. One of the specimens named A. adriatica has a 
delicate round granule (probably an apiculus) at the outer extremity 
of each interval, thus recalling A. marylandica, var. ausonia , Cstr. 
Mr Edmund Grove has proposed to establish a var. approjpinquans, 
for specimens in which one of the compartments is smaller than 
the others, two of the intercompartmental intervals being in conse- 
quence unusually approximated. 
Habitat. — Maryland (Ehrenberg) ; Barbados deposit (Greville !) ; 
Springfield deposit, Barbados (Hardman !) ; Cambridge deposit, 
Barbados (Greville ! Hardman !) ; Newcastle deposit, Barbados 
(Grove!); Piscataway deposit (Johnson, Greville! Roper!);* 
Monterey stone (Greville ! Walker- Arnott) ; Richmond deposit, 
Ya. (Johnson); Rappahannock (Greville); Bermuda tripoli (Dallas); 
Oamaru deposit (Grove!); Indian Ocean soundings, lat. 5° 37' S., 
long. 61° 33' E., 2200 fathoms, Captain Pullen (Greville !); Indian 
Ocean, off Zanzibar (Ehrenberg) ; from Salpoe, Bay of Bengal 
(Wallich) ; Alexandria (Hardman !); Port Natal (Shadbolt) ; from 
Comatulce, Mediterranean Sea (Muller) ; Holothuria, China (Thum); 
South Naparima, Trinidad (Greville) ; Rembang Bay (Deby !) ; f 
Tegel von Mahren, Austria (Deby !). 
* In the collection of Dr R. K. Greville. 
t In a type slide of material from this locality prepared by Herr Thum. 
