44 A MONOGRAPH OF THE 



Tongue narrow, with 4 plates ; the 2 next the median line bearing each a large spine .- no 

 central plate. A spinous buccal collar. 



1. G. nodosa, Mont. White tinged with yellow and pink, with opaque white spots; cloak with a 



scalloped margin, and a central ridge with 1 or 2 rows of tubercles on each side ; branchial 

 plumes 13, simply pinnate. Length 1 inch. PI. 18. 



2. G. castanea, A. and H. Eeddish-brown spotted with white; sides much tuberculated; cloak very 



small, with a reflected margin and a central ridge ; branchial plumes 7 — 9, tripinnate. Length 

 | to 1 inch. PI. 19. 



Genus 3. TRIOPA, Johnston. 



Cloak small, covering the head, with linear or subclavate marginal appendages. Dorsal 

 tentacles 2, laminated, retractile within small sheaths. Oral tentacles 2, cylindrical. 

 Branchial plumes non-retractile. 



Tongue rather broad, with numerous plates, the two innermost on each side bearing large spines : 

 no central plate. 



1. T. claviger, Mull. White; cloak with orange tubercles and the marginal appendages tipped with 

 yellow; branchial plumes 3, bipinnate. Length | inch. PI. 20. 



Genus 4. iEGIRUS, Lov£n. 



Body convex, covered with large tubercles. Cloak indistinct, forming a veil over the 

 head and a tuberculated ridge on each side. Dorsal tentacles 2, linear, smooth, retractile 

 within sheaths. Branchial plumes non-retractile. 



Tongue broad, with numerous, simple, curved, lateral spines : no central plate. An upper 

 corneous jaw. 



1. M. punctilucens, D'Orb. Purple-brown, with darker areas, each containing a central, brilliant, 

 greenish-blue spot; branchial plumes 3, tripinnate, whitish. Length | inch. PI. 21, and 

 Appendix (8), p. iii. 



Genus 5. THECACERA, Fleming. 



Body smooth ; cloak obsolete ;. veil indistinct, variable. Tentacles 2, laminated, retrac- 

 tile within sheaths. Branchial plumes non-retractile, with lateral appendages. 



Tongue with 14 or 16 plates, the 2 inner plates on each side bearing bicuspid spines : no 

 central plate. Small lateral corneous jaws. 



1. T. pennigbra, Mont. White spotted with orange and black; veil bilobed; tentacular sheaths 



bilobed ; branchial plumes 5 ; branchial appendages one on each side, large, bifid. Length 

 i inch. Appendix (9), p. iii. 



2. T. virescens, A. and H. Peach-blossom coloured with green blotches before and behind ; tentacles 



green, with small, plain sheaths ; branchial plumes 5, greenish, edged with white ; branchial 

 appendages, several, tubercular, obsolete. Length T 3 S inch. Appendix (10), p. iv. 



3. T. capitata, A and H. White freckled with greenish- brown ; tentacles with small plain sheaths; 



veil with 2 to 4 orange tubercles on each side, and a row of orange tubercles between the 

 tentacles ; branchial plumes 7, pinnate, tipped with orange ; a stout branchial lobe on each 

 side, also tipped with orange. Length \ inch. Appendix (11), p. iv. 



