198 SCIENTIFIC RESULTS OF THE 
transverse diameter of the pedal ganglion, rather strong. The buccal 
ganglia of roundish form, connected through a very short commissure ; 
the gastro-cesophageal ganglia short-stalked, reaching scarcely one- 
quarter of the size of the former, with one very large and some 
smaller cells.’ 
The eyes with black pigment and shining, horn-yellow lens. The 
otocysts at the slight emargination at the outer margin of the cerebro- 
visceral ganglia, crammed with otokonia of the usual kind. The broad 
leaves of the rhinophoria stiffened in the usual way by long, much 
calcified spicula, perpendicular on the free margin of the leaves. The 
skin of the back crowded with spicula,? mostly very large and much 
calcified; in the rather low (height 0.5 mm.) granules (fig. 2) crowded 
erect spicules. In the insterstitial tissue of the intestines true spicula 
are neither many nor large. 
The mouth-tube about 2.0 mm. long, strong, rather wide, quite as 
usual. The bulbus pharyngeus 3.0 mm. long, with a height of 2.3 
and reaching a breadth of 2.5 mm.; the rasp-sheath also projecting 
1.0 mm. from the hindermost part of the under side of the bulbus. The 
form of, the bulbus and its retractors as usual; the lip-disk whitish, 
clothed with a yellowish cuticula. The tongue of usual form; on the 
shining horny-yellow radula eleven rows of teeth, further backwards 
twelve developed and four younger rows; the total number of rows 
thus twenty-seven.’ The teeth of yellowish color; the height of the 
outermost 0.06, of the next 0.08 mm.; the height reaches at most 
about 0.22 mm. The two foremost rows were rather incomplete, in 
the fourth row were twenty-four, and the number of teeth then in- 
creases to twenty-seven. The rhachis (fig. 3a) rather broad. The 
plates of the usual form,’ with the usual wing-like expansion of the 
exterior part of the body and of the root of the hook (figs. 4, 5); the 
first (fig. 3) with lower hook, which on the succeeding teeth slowly 
! This representation of the central nervous system in most points agrees 
with that of Hancock and Embleton (1. ¢. p. 233, Pl. XVII, fig. 2, 3). 
2 Collingwood (Annals and Mag. of N. Hist., 3 Ser., III, 1859, p. 462) 
mentions the spicules of this species (from the estuary of the Mersey) as 
‘‘very elegant, consisting of a broad embossed plate with a double and 
beautifully serrated edge, terminating abruptly in a blunt apex.”’ 
* Alder and Hancock mention twenty-four rows, whereof eleven were on 
the tongue. ; 
* Alder and Hancock mention twenty-five plates in the rows. 
5 Cf. my Malacolog. Unters. (Semper, Philipp. II, ii), Heft XIV., 1878, 
(Asteronotus), p. 636, 
