SHERPULIDA. 323 
In Hupomatus Meyer figures the opercular stalk toward the base as triangular, with a 
smaller central area than in Pomatocerus and three longer nerves, the muscular band being 
nearest the point of attachment. 
Salensky! (1882) describes the development of Psygmobranchus protensus, which he found 
mature in April and May at Naples, the ova being in gelatinous masses near the outer surface 
of the tube. Development is rapid. The eyes appear before the differentiation of the ganglia. 
He found two ciliated tubes anteriorly on the ventral surface which he thought akin to the 
cephalic kidneys described by Hatschek in Annelids and Mollusks. He considered the 
separate nerve-cords in the Serpulids as secondary, not primitive, and intermediate between 
the widely separated Nemertean trunks and the fused ganglionic series. The free-swimming 
larva becomes surrounded by a delicate membranous tube and by-and-by becomes fixed. 
The subcesophageal ganglia are not separated from the cephalic except by a constriction. 
The young annelid has a distinct head separated by a neck. A primitive blood-cavity which 
contracts rhythmically is formed after fixation, and he thought the blood-vascular system, 
which is formed later, is at first in intimate connection with this. 
Levinsen (1883) made his group Sabellzformia include the Sabellidee and Serpulide. 
He arranges the Serpulids thus:—Frligrana, Apomatus, Pomatocerus, Hydroides, Placostegus. 
Ditrupa, Spirorbis, Chitinopoma, Hyalopomatus, and Protula. He also grouped them 
according to the form of the tubes as follows -—Ditrupa, Filigrana, Spirorbis, Placostequs, 
Pomatocerus, Chitinopoma, Serpula, Hydroides, Hyalopomatus, Apomatus, and Protula. 
Pruvot? (1885) found in Serpula philippr, Morch, four cephalic ganglia, as in the Sabellids, 
and the connection of these with the anterior glands is intimate. The external ganglia give 
off the stomato-gastric. He holds that the operculum represents the first dorsal branchial 
cirrus modified. The * 
filaments. 
Hatschek® (1885) carefully examined the development of Hupomatus uncinatus, Philippi 
(Serpula uncinata) at Messina, describing the segmenting egg and thereafter up to the trocho- 
‘antennee ” (tentacles) on the other hand do not represent branchial 
phore stage with protrotroch, sensory plate, eyes, statocysts, mouth, alimentary canal, 
vent, muscular bands, anal vesicle and head-kidney. He combats Stossich’s view that the 
Gastrula-mouth becomes the anus, since both he and Von Drasche found that the blastopore 
became the mouth. 
In Serpula Cunningham (1888) observes that the neural canals are similar to those of 
Sabellids. : 
De St. Joseph (1894) placed much weight on the structure of the hooks of the Serpulids 
in their classification, and he mentions five different forms. 
1. Hooks with few teeth, and terminating anteriorly in a large tooth pointed like the 
rest :—Gen. Serpula, Hydroides (Hupomatus, Phil., Hucarphus, Morch, Polyphragma, Quatret.), 
Crucigera, Benedict, Protis, Ehlers. 
2. Hooks with numerous fine teeth and terminating anteriorly in a longer and 
more obtuse tooth than the rest:—Gen. Frlograna, Oken, Salmacina, Clap., Filo- 
granula, Lang, Spirorbis, Daud., Pileolaria, Claparéde, Omphalopoma, Morch, Vermilia, 
1 «Arch. Biol., t. 8, 1882, p. 345, pls. xiv and xv. 
2 “Arch. Zool. Expér.,’ 2° sér., t. 11, p. 320. 
3“ Arbeiten Zool. Inst. Wien,’ t. vi, p. 1, Taf. i—v. 
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