Mr. W. C. Hevvitson on new Species q/" Hesparidse. 319 



forming two complete figure-of-eight coils {h), in which a 

 multitude of ova were irregularly scattered, much as in the 

 spawn of Doto^ as represented by Alder and Hancocii (Br. 

 Nudibr. 3I0II. tarn. 3, pis. 5, 6). 



A week later still these ova had become so many actively- 

 revolving embryos. Each chorion, of an oval form, enclosed 

 a single embryo, which rapidly rotated by means of long cilia. 

 The ciliated organs were thick uncouth masses, rather than 

 the flattened symmetric lobes of the infant Doris and Eolis 

 (as figured by A.& H.) ; and the shell appeared more irregular, 

 and much less nautiloid. Some of the embryos were much 

 larger and apparently more advanced than their fellows. 



This specimen, as the preceding, I hope to present, duly 

 preserved in spirit and labelled, to the British Museum. 



The generic name is given in honour of the late Albany 

 Hancock, one of the' conjoint authors of the very beautiful 

 ^' Monograph of the British Nudibranchiate Mollusca." 



The nomen triviale (well-fingered) alludes to the curious 

 appendages of the oral tentacles, and glances also at the 

 digitate incision of the branchial leaves. 



It is not without a strong sense of the evil of " thrusting 

 uncalled-for synonyms into the nomenclature of science" that 

 I venture to give names to these forms ; and my rqisgiving is 

 the greater because my position, remote from the centres of 

 literature, and my protracted abstention from descriptive 

 natural history, have too much shut out from my cognition 

 the advance of science. The creatures described were, how- 

 ever, so novel to me, and so attractively interesting, that I can 

 only venture and hope. 



EXPLANATION OF PLATE XI. 



a, h. Hancockia eudactijlota, viewed laterally and dorjally, magnified -f . 



f. The anterior parts, from beneath. 



d. A dorsal tentacle and sheath. 



e. The same, obliquely from above, without the sheath. 



f. A branchial leaf (drawn diagrammatically). 



g. The same, in its ordinary condition. 

 h. Spawn. 



XL. — Descriptions of twenty-three neio Species o/" Hesperidae 

 from his ovm Collection. By W. C. HewitsoN. 



Myscelus Orthrus. 

 Alis utrinquerufis: anticis lasi margiiiibusqu > fuscis punctis novera 



