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TI-IE VOYAGE OF H.M.S. CHALLENGER. 
pinnate ; the foot is large as in Doris. In internal structure, however, this genus is 
widely removed from Doris , and resembles more closely the Phyllidiadse. In the central 
nervous system the ganglia are very concentrated. The bulbus pharyngeus is elongated 
and tube-like, the buccal ganglia and salivary glands lying at its hinder end ; there is 
no trace of mandibles or tongue, the bulbus itself forming a suctorial organ. There is a 
large inferior ptyaline gland. 1 In the pericardium is a special system of gill-leaves. 
There is a large sanguineous gland. The liver is deeply cleft at its posterior end (for the 
retractor branchiae longus muscle). The hermaphrodite gland covers the liver ; a sper- 
matheca and spermatocyst are present ; the end of the spermatic duct, and the glans are 
armed with series of small hooks. 
The genus is confined to the tropics, or at least the warmer seas ; nothing is known of 
its habits and mode of life. The ribbon-shaped spawn of a few species has been detected, 
but nothing is known of their development. 
The following is a list of the species that have been described : — 
1. Doriopsis nebulosa, Pease. 
Pacific Ocean. 
2. Doriopsis scabra, Pease. 
Pacific Ocean. 
3. Doriopsis viridis, Pease. 
Pacific Ocean. 
4. Doriopsis affinis, Bergh. 
Pacific Ocean. 
5. Doriopsis tristis, Bergh. 
Philippine Sea. 
6. Doriopsis rubrolineata, Pease. 
Pacific Ocean (Huaheine Islands). 
7. Doriopsis tuberculosa (Quoy et Gaimard). 
Doris carbunculosa, Keiaart. 
Pacific and Indian Oceans. 
8. Doriopsis australis (Angas). 
Pacific Ocean. 
1 With respect to the acidogene nature of the glanduke ptyalinse and salivales : see, Krukenberg, Vergl. physiolog. 
Studien, Bd. v. 1881, pp. 69-70. 
