KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 52. N:0 16. 41 
right nephridium, as far as to the upper side of the visceral ganglion. It consisted, 
as far as could be seen, of epithelial plaits clothed by very high cylindric cells with 
contents deeply tinted with haematoxylin towards the exterior ends. It was innerved 
by the posterior pallial nerve. 
On the general place of the osphradium at the base of the gill axis no speci- 
alization of the epithelium and its innervation was to be observed. 
Muscles. Besides the two adductors, of which the anterior one (ad.) is longer 
than the posterior, as the muscular impressions on the shell indicate, there exist 
the pallial and the siphonal muscles, as well as the foot retractors. The last-named 
are much reduced as a consequence of the vestigial nature of the foot. "They eman- 
ate as a single cord from the musculature of the visceral hump and penetrate the 
nephridia in front of the visceral ganglion. They soon disappear, still as a single 
cord, in front of this ganglion long before arriving at insertion in the shell. 
b. Gastropoda. 
Prosobranchia. 
FAM. FISSURELLIDAFE. 
Glyphis jukesi REzrvE. 45 miles W. S. W., 66—384 feet ('/e, ""/r); and 42 miles 
W. S. W., 60 feet ('”/+), many sps, max. 1. 35 mm (the latter locality). Distribution: 
Gulf of Oman: Ormara Bay (MELVILL & STANDEN 1901); all round the coast of 
Australia (PILSBRY 1890, HEDLEY 1910). 
G. singaporensis RErvE. 45 miles W. S. W., 70—72 feet (!'/1), 2 sps, max. 1. 
16 mm; 42 miles W. S. W., 70 feet ("”/s), 1 sp., 1. 17.5 mm. The specimens agree in 
shape, colour, and sculpture, with figures 100 and 101 in REEvE's Conch. Icon. 6, 
1850. Most characteristic are the indistinet broad radii, to the number of 8, best 
visible towards the margin, and the rather fine latticed sculpture, in which the 
radiating ribs dominate over the concentric threads. On the inside the radii shine 
through; here there appear also fine, opaque, white radiating lines such as PILSBRY 
(Man. of Conch. XII, 1890, p. 219) mentions. Distribution: Singapore (REEVE), 
Maldives and Laccadives (E. A. SmMmitH 1903), Andaman Isl.; Chagos Archipelago 
(MELVILL 1909), Queensland (HEDLEY 1910). 
G. quadriradiata RErvE. 45 miles W. S. W., 60—66 feet ('"/;), 3 sps, max. Il. 
14.3 mm. The specimens are quite similar to fig. 108 by REEVE (Conch. Icon. 6 
Fissurella) in their very characteristic colouration (4 rays forming a cross) and 
the shape of their foramen, which has excavated sides, in which it differs from &G. 
räpelli, which is, further, more elevated. The largest specimen had, besides the 4 
dark cross rays, a greenish tint towards the margin, and some of its costae were 
stained with purple. The under margin is crenelated in an alternating manner, so 
that between two deep slits there is one median shallower, and on both sides of it 
K. Sv. Vet. Akad. Hanäl. Band 52. N:o 16. [ 
