270 DR. A. RATTRAY ON THE ANATOMY, PHYSIOLOGY, 
Distribution and Varieties. 
Said to be ** amongst the most abundant of the Pelagic Mollusca, and float in myriads 
on the surface of the Mediterranean and Atlantic” (Owen); the Firolidæ are not so 
numerous in the Pacific, at least its eastern or American half. Thus, during several 
voyages across the equator, between Vancouver Island, in 484° N. latitude, and Valparaiso, 
in 33° S. latitude, extending over 170 days, during which the towing-net was kept con- 
stantly going when practicable, they were met with only eleven times, six bringing 
single specimens, and eight the highest number procured at one haul Carinaria and 
Cardiapoda are by no means common ; those obtained were chiefly Firola and Firoloides, 
particularly the latter, sixteen of the twenty-five being Firoloides. The Atlantidæ are more 
numerous than either. The subjoined Table will show the different varieties thus ob- 
tained, the locality, number, &c. Although most abundant near the equator, where high 
temperature favours the development of aquatic life, the Table shows that their range of 
distribution in the Pacific is wide, as with the Heteropoda generally. In this instance 
it spread over 77° of latitude (viz. from 40° N. to 31? S.) on the one hand, and on the 
other from mid-ocean to within sixty miles of the American shore; and further obser- 
vations will doubtless widen the area. | 
TABLE. 
: ud Locality. Sea. 
When obtained. Name. SN Reference. 
z 8| lat. Long. |Temp.| Sp. gr. 
ae 3 °F. Plate fig. 
Feb. 11, 1860... ... a. . (Carinaria, or Carinaroides(muti-| 1 |Equator 115 W.| 76 |1026 | XLIV. 15. 
lated, visceral nucleus absent). i 
( |Carinaroides pedune 254 
| Cardiapoda pedunculata (D' Orb. 
oy. + 
July 8, 1861 ...... id Cardiapoda carinata (D'Orb. 4 | 31°$8. 73 W.| 55 [10974 XLIV. 16. 
oy. 
| [Firola caudina (Rang) ...... J 
May 4, 1861 .. } { Carinaroidos., ¿Dio Fy 1 | 18°N. |115 W.| 81 |1025 XLIV. 14 
May 14,1861.. | **| Ÿ | [Carinaroides................ 2 |Equator| 1193 W. | 79 |10251 } is 
Sept. 7, 1801 ...... a Seen 1 | OS N. [187 W.| 71 11028 | XLIV. 32 
Feb. 7, 1860 se: TOMAR oe rs ee 1j 45.414110 Wit 22. 11026, 11 
Feb. 11, 18602 .: 55. IFisolddes- co. u 0e 2 |Equator| 115 W.| 76 |1026 | >XLIV. 18. 
April 22, 1861. (HINC vs su 1 | 40° N. | 1272 W. | 562 | 1029 ) 
( Firola Keraudrenii 2 
Feb. 14,1860.. .... aq | Tirola Desmarestia `... 3| 2N.|120 W.| 78 |1025 | 
irola Keraudrenii ...... 5 
May 14, 1861... ¿ | Mies Dee oe 8 |Equator| 1194W. | 79 | 10254 pue 19 
: Firola Keraudrenii ...... 
May 16,1861. ..... 4 { Pole Dae o 1| 58. 1200W.| 79 |10953 |) 
March 11, 1864....| y |Firoloides or Anops (South In- | 1 | 3508, 73 E. | 69 |1027 | XLIV. 20. 
dian Ocean). : ; 
Many interesting problems remain to be solved with regard to these animals, e. g. 
whether they are arctic and subarctic, as well as temperate and tropical forms ; and if so, 
