of the Fishery Board for Scotland. 246 



appears to consist of two coalescent segments, is of a sub-cylindrical form 

 but tapers slightly towards the distal extremity ; it is about one-third 

 longer than the breadth at the widest part and nearly twice the entire 

 length of the next segments. The third segment is only about half the 

 length of the second one. 



The furcal joints are each provided with six setae arranged as shown in 

 the drawing (fig. 10, pi. xiii.), but one of the setae is very small. 



The length of the specimen represented by the drawing is 3'1 mm., 

 which is somewhat larger than that stated by Dr. Giesbrecht. No males 

 of this species have been observed hitherto. 



M. gracilicauda has been collected at the following places : — 



Firth of Forth, above Queensferry, June 26, 1890 ($). 



Firth of Forth, off Musselburgh, September 29, 1892 ($). 



*35 miles east of May Island, Firth of Forth (per s.s. " Glenogle "), 



August 20, 1903 ($). 

 Firth of Clyde, Whitefarland Bay, Arran, July 6, 1899 ($). 

 Firth of Clyde, near head of Loch Fyne, November 28, 1899 ($). 



Monstrilla anglica, Lubbock. PI. xiii., fig. 13; pi. xiv., fig. 12 14. 



1857. Monstrilla anglica, Lubbock. Ann. and Mag. Nat. Hist. 



(2), vol. xx., p. 409, pi. x., fig. 7, 8. 

 1900. Monstrilla (?) dana3, Scott, 18th Ann. Eept. Fishery 



Board for Scotland, pt. iii., p. 398, pi. xiii., fig. 15-20. 



Description of the Female. — The specimen represented by the drawing 

 measures 3*2 mm. (nearly §• of an inch); it has a general resemblance in 

 size and structure to Monstrilla longicornis, but is scarcely so robust (fig. 

 13, pi. xiii.). 



The antennules are elongated and slender and indistinctly three-jointed • 

 the basal joint is as usual very short; the next, which is not very clearly 

 defined, is also small, but longer than the basal joint ; the remaining 

 portion consists of a single piece which may be made up of two or three 

 coalescent joints (fig. 12, pi. xiv.). 



The fifth pair of thoracic feet are sub-cylindrical in outline, and nearly 

 twice as long as broad ; each foot is furnished with two elongated apical 

 setae, and the inner margin, which is nearly straight and shorter than the 

 outer margin, terminates in a small rounded process, beyond which the 

 distal portion of the foot becomes narrower as shown in the drawing 

 (fig. 13, pi. xiv.). 



The genital filaments are scarcely equal in length to the furcal setae. 



The abdomen appears to consist of three segments ; the first segment 

 is about twice the length of the second, while the second is about one and 

 a half times the length of the third. 



The furcal joints are each furnished with six setae (fig. 14, pi. xiv.). 



Habitat— Firth of Forth, west of May Island, July 26, 1901 ; thirty- 

 five miles east of May Island, August 20, 1903, per s.s. "Glenogle." 

 Females only were observed in both gatherings. 



This species resembles M. longicornis in size, in the elongate antennules, 

 and to some extent in the structure of the abdomen, but differs very 

 distinctly in the armature of the fifth pair of thoracic feet, and in 

 possessing six instead of five furcal setae ; and the integument appears to 

 want the minutely granulated structure observed in M. longicornis. 



The specimens recorded by me in Part III. of the Eighteenth Annual 

 Report of the Fishery Board for Scotland from the Firth of Clyde appear 

 to belong to Lubbock's Monstrilla anglica', these specimens were 



* This specimen was of a fine green colour. 



